CELEBRITY JUSTICE ™

Iggy Azalea used an Atlanta producer to score her deal with Def Jam, then kicked the guy to the curb and shorted him by more than a million bucks ... according to the suit he just filed against her.

Jon Jon Traxx says Iggy signed a deal to record with him in 2009 and over the next 2 years he nurtured her career by setting up shows, getting her a stylist and introducing her to influential record biz execs.

In the suit, he says Iggy stopped talking to him after she signed with Def Jam. Traxx says he and Iggy agreed to terminate their contract in 2013, but there were strings ... which called for him to get further compensation.

Taylor Swift's security team sprung into action when a man showed up on her NYC doorstep Tuesday evening ... TMZ has learned.

Taylor's guards detained the unidentified man, and someone called 911. NYPD and NYFD responded to Swift's Tribeca home around 6 PM and described the man as "disoriented" as he was handcuffed.

From the video, it appears he had a duffel bag ... which police searched. Law enforcement sources described him as "emotionally disturbed," and he was taken to a hospital for evaluation.

Taylor was not home. It's unclear if he made any threats or actually gained access to her crib.

So far, he hasn't been booked for any crime.

Vin Diesel is giving his former business partner a triple X screw job ... according to a lawsuit the guy just filed against Diesel.

In the docs, George Zakk says he ran Vin's production company, One Race Films, since 1995 -- and their deal called for him to get a piece of the pie every time Vin made a movie.

Zakk says he was supposed to get $250k to $275k and a credit of at least producer on each film. He says everything was cool on movies like "xXx," "Chronicles of Riddick" and "The Pacifier."

But Zakk says he's getting the shaft on the "xXx" sequel set to come out next year.

In the suit, he says although he stopped running One Race Films in 2007 ... he believes his deal lives on -- so he deserves his fee and credit for the sequel.

The DEA is currently at Prince's Paisley Park home, executing a search warrant, and TMZ has learned there is an active federal investigation into doctors who prescribed meds to Prince ... sources connected with the investigation tell TMZ.

Our sources say the feds are conducting the probe under a series of federal laws targeting doctors who sell prescriptions to drug abusers. Our sources say this is precisely the reason for the investigation.

The laws also outlaw doctors and pharmacies who falsify record or forge prescriptions.

Our law enforcement sources tell us ... there's an additional element ... crossing state lines to violate prescription laws. Our sources say the feds are also looking at the son of the rehab doctor who flew to Minnesota with a backpack full of synthetic opiates. The son, Andrew Kornfeld, was at Prince's home when he died. We're told Andrew is under the federal microscope.

A doctor who treated Prince, wrote him prescriptions and was present at Paisley Park when the singer died has mysteriously left the medical center where he worked.

Cops obtained a search warrant for North Memorial Medical Center where Dr. Michael Todd Schulenberg worked. The warrant asks for all medical records, documents, reports, charts, photos, prescriptions, doctor's notes and medical notes for Prince Rogers Nelson.

According to the warrant, cops interviewed Dr. Schulenberg, who acknowledged he treated Prince twice in April ... the last time the day before he died. The doctor told cops he ran tests on the singer and he was at Paisley Park the day Prince died to drop off the test results.

The doctor also told cops he prescribed medications for Prince, which were supposed to be filled at Walgreens.

TMZ broke the story ... Prince had gone to Walgreens 4 times in the week preceding his death. The warrant mentions the plane trip where Prince OD'd 6 days before his death. We broke the story about the emergency landing and that the drug was Percocet.

Prince has a biological son who is not mentioned in the probate case ... at least according to the alleged son.

Carlin Q. Williams of Missouri is 39 years old and filed legal docs claiming his mom met Prince in the lobby of the Crown Center Hotel in Kansas City, Missouri back in July 1976. She says in an affidavit she drank wine with the singer and checked into a room and had unprotected sex.

According to Carlin's mom, Marsha Henson, she didn't have sex with anyone 6 weeks before and didn't have sex with anyone during her entire pregnancy.

Carlin -- who is currently in federal prison for gun possession -- now wants an order testing Prince's DNA samples against his to unlock the mystery.

Bristol Palin and baby daddy Dakota Meyer are finally getting along as parents ... and in the ultimate show of goodwill, she is signing off on the baby getting dad's last name.

According to court docs ... Meyer filed a petition to rename the couple's 5-month-old daughter from Sailor Grace Palin to Sailor Grace Palin Meyer. He also said he's now listed on the baby's birth certificate.

Bristol included her own doc ... signing off on the name change.

As for their custody woes ... we're told both Bristol and Dakota are committed to co-parenting and getting along. They even spent Mother's Day together in Alaska.

Nerlens Noel says he's NOT the renter from hell -- claiming allegations he absolutely destroyed the Philly home he was renting last year are pure B.S. ... adding that he never threatened to kill the owners.

TMZ Sports broke the story ... the 76ers star was sued for more than $40,000 by the property owners who say the 22-year-old trashed the place so bad, the place looked like a bomb went off inside.

Among the accusations ... carpet destruction, toilets clogged with cotton balls and feces, water damage, broken appliances and allegations he left a tombstone on the front step as a death threat.

Now, Noel has finally fired back in legal docs of his own -- adamantly denying he went "Project X" on the place. In fact, Nerlens says he tried to work with the owners to repair the carpet damage even though he wasn't entirely convinced he damaged them in the first place.

But Nerlens is clearly most upset about the tombstone allegation -- insisting it was just a Halloween decoration that was left on the property a few weeks before the holiday ... and doesn't amount to a threat.

Chris Massey dodged serious legal trouble in Las Vegas as prosecutors have decided not to pursue domestic violence charges.

The Clark County D.A. rejected the domestic violence case against the "Zoey 101" star, citing insufficient evidence. TMZ broke the story -- Massey got arrested last month after he allegedly pushed GF Cassalei Jackson inside Marquee Nightclub.

Minnie Driver's wreaking havoc on her neighbor by chucking baby food jars filled with black paint against his walls ... according to a new lawsuit.

In the docs, Daniel Perelmutter says Driver's made it impossible for him to finish construction on his home, and her obscenity-laced tirades are stressing him out -- a serious issue, since he says he's had a heart transplant.

Daniel's asking the court to remove the electronic gate he used to share with Minnie because she's cut off his access. He also says she's thrown construction materials on his property and blocked in his workers for up to 8 hours -- not to mention those baby food paint grenades.

Keanu Reeves is once again being courted to join the resistance and save humanity ... only this time it's not Morpheus ... it's an obsessed fan who thinks "The Matrix" is real life.

According to legal docs ... the LAPD is looking for a guy who showed up at the actor's home last October and placed a FedEx envelope in his mailbox, offering up a cell phone number with this instruction: "I will call the cell provided tomorrow. We need to meet as I have already started building the new world. #masterbuilder."

Cops believe the guy has an obsession with Keanu's character, Neo, from "The Matrix" movies ... the cell phone reference is actually a nod to the first movie.

Keanu told cops he's afraid for his safety because the guy knows where he lives ... and he thinks the guy suffers from some type of mental disorder.

The LAPD is on the case.

Amber Rose is like "Highlander" -- there can be only one -- and she's in the middle of a legal dogfight to win the exclusive right to make bank off her name.

Amber filed legal docs to trademark her name so she can market the hell out of it. Enter Amber Rose Kelly -- an up-and-coming country star -- who filed her own docs claiming she, not Kanye's ex, has the right to lay claim to the name.

ARK is trying to convince the honchos at the Trademark Office she's the famous one ... an award-nominated former child actor, singer, songwriter, recording artist, model and photographer. By contrast ARK claims Amber is nothing more than a former stripper who parades down the Sunset Strip in a bathing suit.

ARK also says prior to 2009 ... she was the only Amber Rose who appeared in Google.

The guy who allegedly threatened to kill Scientology leader David Miscavige is a free man ... after pleading no contest to making death threats and stalking the church leader.

Andre Barkanov, a 47-year-old Illinois resident, was sentenced to 1 year in county jail, but got credit for time served and won't have to spend another day behind bars.

Barkanov was also hit with five years of formal probation and a 10 year protective order, requiring him to stay clear of Miscavige and the church. He also has to complete a 1 year substance abuse program.

What Katt Williams calls a Good Samaritan act ... prosecutors call grounds for another criminal charge against the comedian.

Law enforcement sources tell TMZ ... he's been charged with one count of misdemeanor battery for the incident in L.A. in March where Katt allegedly struck bystanders in self-defense. Katt told us the guys were cracking short jokes on him after he ran to help victims in a car crash.

Meanwhile, back east ... prosecutors in Georgia filed a motion to revoke his bond in his bodyguard assault case. The Hall County D.A. said his last arrest -- for allegedly throwing a salt shaker at a restaurant manager -- was the last straw.

If a judge signs off, Katt could be locked up until he goes to trial. He also faces 6 months in jail for the L.A. case.

At this point, Katt's lawyers are booking more gigs than he is.

Chyna was seriously struggling before she died -- so much so, police found her wasted and passed out on the ground outside her apartment building ... TMZ has learned.

Law enforcement tells us they got a call in November for a woman lying unconscious at 7 AM in Redondo Beach, CA -- and when they arrived, officers found Chyna. We're told she was slurring her speech, had bloodshot eyes and reeked of booze.

Cops say Chyna admitted drinking wine the night before and said she decided to sleep outside because she was struggling with her keys. She was also carrying nearly $20k in cash she says she made at an autograph session.

Paramedics on scene determined she was too drunk to take care of herself, and cops booked her for public intoxication.

Chyna was found dead on April 20. Her cause of death is still under investigation.

Prince's blood will be under a microscope soon at the request of the special administrator of his estate.

A judge in Carver County authorized Bremer Trust to order DNA testing of the late singer's blood ... for purpose of addressing "parentage issues." It's clear Bremer is expecting alleged family members to come out of the woodwork to get a slice of Prince's fortune.

According to docs, there is a sample of Prince's blood being held at the Medical Examiner's office for testing.