RIP

The cast of "Glee" -- along with several producers -- knew Cory Monteith was battling a heroin addiction earlier this year and were the catalyst in his decision to go back to rehab, TMZ has learned.

Sources connected to the production tell us ... it was no secret Monteith was off his game back in March -- and it became clear he was relapsing, specifically with heroin.

We're told the cast and the producers became very concerned ... and knew they had to address the issue with Cory.

Sources say ... the group sat down with Cory and had an "open conversation" with the actor -- stressing how much they cared about him and wanted him to get help.

One source tells us Cory was very receptive -- "It wasn't met with resistance ... He was always so grateful and aware of how fortunate he was."

"The decision was to best help our friend. The needs of the show fell second to his well-being."

Cory voluntarily checked into rehab at the end of March for a 30 day stint ... but despite his efforts, he couldn't defeat his demons, and last week, he died from a lethal mixture of heroin and alcohol.

He was 31.

3:10 PM PT -- Officials are currently addressing the media about the death investigation.

Cops wouldn't delve into specifics when asked if they found drugs in Cory's hotel room, but they certainly insinuated it ... saying, "There was evidence in the room that was consistant of a drug overdose."

Cory Monteith died from a lethal combination of heroin and alcohol ... this according to Canadian authorities.

The British Columbia Coroners Service says an autopsy and toxicological analysis show that the 31-year-old "Glee" star died from a "mixed drug toxicity, involving heroin and alcohol."

Monteith's body was discovered by staffers at the Fairmont Pacific Rim hotel in Vancouver, Canada on July 13.

Monteith had struggled with addiction for years and had been to rehab earlier this year.

Monteith had said he began struggling with drugs and alcohol as a young teenager.

Story developing ...

Cory Monteith was leading a double life -- a hard-working, "Glee" star in L.A. struggling to stay clean ... a hard-partying substance abuser in Vancouver.

CORY'S L.A. LIFE

Our sources say Cory's GF Lea Michele and his "Glee" cast knew his struggles all too well and spent a lot of time keeping him clean and sober. We're told Cory never showed up on the set under the influence of anything and most of the time abstained from drugs and alcohol.

The pic above shows the last trip Cory and Lea took together -- it was taken on June 18th in Fire Island, where they visited a friend on a movie set. We're told Cory was sober the entire time.

There were, however, lapses, which is why he checked into rehab in April.

CORY'S LIFE IN VANCOUVER

Our sources say Cory's resolve to stay clean dissipated whenever he returned to his native Canada. That's where he became a drug addict with a serious drinking problem.

Corey went back to Vancouver many times, and hung out with many of the friends who helped fuel his addiction. We're told alcohol and drugs were always involved.

Our sources say Cory's family was aware he reverted back whenever he went North of the border, and they tried in vain to help. We're told as family members became alarmed recently and began making a full-court press ... Cory became distant.

Somehow, Cory was able to compartmentalize his life into a tragic tale of 2 cities ... and the city where he slipped became the city where he died.

Michael Jackson could have raked in as much as $1.5 billion had he lived ... at least that's what an entertainment money man told jurors today in MJ's wrongful death case.

Accounting guru Arthur Erk testified ... Jackson could have earned minimum $1.1 billion if he performed a worldwide concert and showcased his music in Las Vegas. And Erk felt if ticket prices were high enough, the figure would soar to $1.5 bil by the time Michael turned 65.

There are a couple of problems. First, MJ never planned a worldwide tour. The "This Is It" tour was limited to London. Second, the family is seeking more than $40 billion.

Another interesting thing ... Erk said he deducted what he felt Jackson would have spent between age 50 and age 65, when he hypothetically would have retired -- $134 million.

Oh the struggles of living on a budget.

Grief-stricken fans in 2 cities are showing their love for Cory Monteith ... putting together makeshift tributes outside Paramount Studios and the Vancouver hotel where he died.

Fans placed candles, flowers, photos and messages to Cory in front of Paramount Studios -- where he taped "Glee."

The other memorial is in front of the Fairmont Pacific Rim Hotel (below) ... where Cory was found dead​ on July 13th.

As we previously reported ... Cory died alone in his 21st floor hotel room. Cause of death is still unknown. An autopsy is scheduled for Monday.

These are some of the last photos ever taken of Cory Monteith -- snapped just days before he was found dead in a hotel room -- while the "Glee" Star was hanging with friends and drinking alcohol.

Sources tell TMZ ... the pics were taken on July 6th, the same day Cory checked-in to the Fairmont Pacific Rim hotel in Vancouver ... where he was found dead one week later.

In the pics, Cory and a few buds are seen hanging out at The Shop -- a local coffee house and clothing store for people who love motorcycles.

We spoke to the owner, who tells us, Cory came in ... was extremely friendly and really interested in choppers ... even sitting on the owner's bike.

We're told he and his friends chilled for awhile -- laughing and drinking beers. One source on-site said Cory knocked back 3 cold ones over the course of a few hours -- despite his recent stint in rehab -- but didn't seem out of control or wasted. He was perfectly nice.

Cory's not physically seen drinking in the pics ... but the Lea Michele doppelganger he's standing next to -- who we're told is just a friend -- is seen clutching two beer cans. Possibly because cameras were around ... and Cory has been open about his substance abuse issues.

As TMZ previously reported ... Fairmont hotel staff found Cory dead in his hotel room Saturday, after spending Friday night out with friends. He was 31.

Now here's Cory's best moment in "Glee" history ... R.I.P.

When you think of Whitney Houston you think ... "I Will Always Love You" -- and now you always will, because it's engraved on her tombstone.

Whitney's grave at Fairview Cemetery in Westfield, New Jersey was finally given a headstone last week, after sitting vacant since her death in 2012.

The epitaph on the new heart-shaped marker reads: "Whitney E. Houston Aug. 9, 1963 -- Feb. 11 2012 ... THE VOICE ... 'I Will Always Love You'."

Interestingly, while Whitney made "I Will Always Love You" famous in "The Bodyguard" -- it was written, and originally performed, by Dolly Parton.

If you're thinking they should've gone with lyrics from "Greatest Love of All" ... "Saving All My Love for You" ... or "I'm Every Woman" -- yeah, she didn't write those either.

Whitney is buried next to her father ... per her wishes.

Cory Monteith -- who famously played Finn Hudson on the TV show "Glee" -- died early Saturday morning in Vancouver ... he was 31 years old.

According to police in Vancouver the actor was found dead in his hotel room on the 21st floor of the Fairmont Pacific Rim Hotel around noon ... when staffers went to check on him after the actor missed his check-out time.

In a press conference, officials said the actor was "clearly deceased" -- and had been so for several hours -- when police arrived on the scene.

Cops say Cory checked-in to the Fairmont on July 6th and was scheduled to leave July 13th. It is unclear why he was in Vancouver, but cops did mention he's from Canada and visits often.

The night before his death, Cory was seen in his room hanging with friends, before hitting the town ... but came back early Saturday morning ... alone.

Cops say "it was not immediately apparent" what caused his death, but no foul play is suspected. An autopsy is scheduled for Monday.

A rep for the actor says they are "in shock and mourning this tragic loss."

As TMZ previously reported, Monteith voluntarily checked himself into a treatment center back in April, admitting he had substance abuse issues. It was his second time in treatment.

Prior to that, Cory had been open about his problems with drugs. Back in 2011 he told Parade Magazine, his family and friends were so afraid he "could die" they staged an intervention. He was 19 at the time.

He explained that his drug use consisted of "Anything and everything, as much as possible." Adding, "I had a serious problem."

"Glee" co-star Matthew Morrison took time out of a performance Sunday to pay tribute to Cory Monteith ... in the most "Glee" way possible ... belting out a Broadway show tune.

Matthew -- who plays Finn Hudson's mentor / teacher on the show -- played a gig at 54 Below in NYC. Prior to the set, Matthew addressed the tragedy of Cory's sudden death and referred to the actor as a brother ... as reported by the NY Times.

Matthew then changed his opening number -- and dedicated the song to Cory.

He chose "What I Did For Love" -- a show tune from "A Chorus Line" -- which was also featured on "Glee" Season 2 and sung by Lea Michele.

Cory Monteith appeared the picture of happiness -- giggling and laughing with girlfriend Lea Michele -- this just a few weeks before he was found dead in a hotel room ... possibly of an overdose.

In this video, shot about a month ago at LAX, Cory and Lea arrive hand-in-hand looking happy and healthy. Even our photog tells the couple, "You look like a million bucks."

At the time, Cory had recently completed a month-long stint in rehab ... for admitted substance abuse issues.

As TMZ previously reported ... Cory was found dead in a Vancouver hotel room Saturday, alone, after spending Friday with friends. There are reports drugs may have played a role.

Beyonce interrupted her own concert last night to take a moment of silence for Trayvon Martin ... right after news broke that jurors found his shooter, George Zimmerman, not guilty.

It happened at Bey's Nashville concert Saturday. About 30 minutes before the singer took the stage, news broke that Zimmerman was acquitted of both the 2nd degree murder charge and manslaughter charge in the shooting death of 17-year-old Trayvon.

Michael Jackson's buttocks were so scarred and infected from long-term drug injections ... the singer's thickened skin nearly broke his doctor's syringe -- this according to the doctor's testimony.

Dr. Stuart Finkelstein -- who cared for MJ back in 1993 during his "Dangerous" tour -- sat for a deposition earlier this year in Katherine Jackson's wrongful death lawsuit against AEG, describing the signs of MJ's drug addiction, and the testimony was just shown to the jury this week in court.

We got video of the depo and the details are crazy -- Finkelstein described one incident, saying, "I attempted to give [Michael] a shot of Demerol [a painkiller] but his buttocks were so scarred up and abscessed that the needle almost bent."

Finkelstein said the scarring resulted from "significant, extensive" shots of drugs over time.

The folks at Lifetime did a bad thing ... they rented a car for their Anna Nicole Smith flick, but returned it all dinged up -- so says the owner threatening to sue over the damage ... all $200 worth.

A woman named Cherry Banez says she agreed to let the movie rent her 1995 red Mercedes SL500. The car was used in a scene where Anna Nicole flashes her boobs at a trucker. Classic.

Anyway, Cherry says the car came back damaged and the people responsible have failed to cover all the costs. In her letter threatening legal action, Cherry says she was actually paid back for most of the repairs, EXCEPT ONE -- the busted car speaker. Bill amount: $200.

Totally worth the legal bills.

It's not surprising, but it's official ... Kris Kross rapper Chris Kelly died from a drug overdose.

An investigator from the Fulton County Medical Examiner's Office in Atlanta said a toxicology screening showed the 34-year-old died with a fatal mixture of drugs in his system.

The investigator didn't specify which drugs, but as we reported, Chris' mother told police the rapper had been doing cocaine and heroin the night before he died on May 1st.

The video TMZ posted -- showing a wasted Chris trying to rap just hours before his death -- appears to back up the Medical Examiner's findings.

In addition to the footage, Kelly also had a long history of drug abuse.

The mystery into the death of Doink the Clown could be SOLVED in the next week ... 'cause officials have completed the autopsy on the ex-WWE star and are expecting results in a matter of days.

After Doink passed away Friday in Plano, Texas ... officials launched a homicide investigation into his death.

One law enforcement source tells us it appears Doink's death was "accidental" ... but the source wouldn't say if investigators believe drugs were involved.

The Plano Police Department tells TMZ ... its lips are sealed on the case until the investigation is complete ... which could happen as early as next week.

The semi-pro football player that Aaron Hernandez allegedly shot and killed was laid to rest Saturday.

Odin Lloyd's funeral took place at the Church of Holy Spirit in Boston. Friends, relatives, and well-wishers all showed up to pay their respects.

As TMZ previously reported ... Hernandez has been charged with Odin's murder, after his body was found not far from the ex-NFL star's home. Prosecutors claim the killing stemmed from an incident that occurred between the two men at a nightclub.