Asking Larry Birkhead about Justin Bieber's recent paternity issues is just too perfect ... considering he was involved in one of the most famous DNA tests ever.

You'll remember ... Birkhead found out he was the father of Dannielynn, Anna Nicole Smith's daughter, after a drawn out paternity battle in the Bahamas in 2007 that involved Howard K. Stern and even Prince Frederic Von Anhalt.

Smart money is on Justin learning the exact opposite news soon.

Larry Birkhead says Anna Nicole Smith's Estate is threatening legal action over the opera titled "Anna Nicole" ... TMZ has learned.



The opera --- playing now at the Royal Opera House in London -- is about Anna's life, and features a very large woman with big boobs loosely resembling Anna.

Larry tells TMZ the producers never contacted Anna's estate or him.  They also didn't offer Larry an advance screening.  Larry says the opera is like "a sleazy tabloid."

Birkhead says the estate is now weighing its legal option.

And, Larry adds, "If [the producers] are not careful, they'll get more than diet pills in the mail."

Larry Birkhead returned to an L.A. County Superior courtroom this morning to continue spilling his guts about Anna Nicole Smith's prescription drug use.


On Thursday, Birkhead testified that he saw Smith take numerous prescription drugs -- but claims that Anna had told him that she wasn't an addict. Birkhead also told the court that Anna insisted she had a high tolerance for certain meds.

Howard K. Stern, Dr. Khristine Eroshevich and Dr. Sandeep Kapoor are all facing charges of conspiring to unlawfully provide drugs to Anna Nicole. They have each pled not guilty.

Larry Birkhead is prepared to tell a jury that he knew his baby mama Anna Nicole Smith was addicted to drugs for years ... this according to court documents obtained by TMZ.



It's all part of the State of California's case against Anna's doctors -- in which they're accused of illegally providing prescription medications to the late starlet.

According to the docs, filed in L.A. County Superior Court, the prosecution says Birkhead has "personal knowledge of Anna Nicole Smith's drug activities, gleaned from years of personal observation."

The lawyers defending the doctors are trying to exclude Birkhead's testimony, saying he's not "qualified" to testify on whether Smith meets the legal definition of an addict.

But in the docs, the prosecution explains that when Birkhead says Anna was an "addict" he is "saying that [he] personally observed her using controlled substances in an uncontrolled way over a long period of time."

The judge is expected to make a ruling on the issue shortly.

We tried asking Larry Birkhead about Howard K. Stern's arrest -- but he wasn't talking. His tongue was too tired from the workout it got a little earlier that night ...


When asked if he's been contacted by any lawyers in the wake of the new Anna Nicole Smith drama, Larry responded, "I've got lawyers on speed dial."

How many times can a guy say he didn't have sex with another guy?

Larry Birkhead was deposed for ten hours (yes, we counted!) yesterday in the defamation lawsuit filed by Howard K. Stern against Rita Cosby.

In a book Cosby wrote last year, she claimed Anna Nicole Smith had a video of Stern and Birkhead having sex.

She may not be blonde, but the gal getting flirty with Larry Birkhead last night at One Sunset definitely has two other things in common with his babymama, Anna Nicole.

It's impossible to get Robin Williams to answer a serious question -- and he'll use whatever accent necessary to dodge the issue.

Also in L.A.: Mario Lopez played Laker cheerleader, Larry Birkhead got overshadowed by Chris Evans, Dog Chapman went out with his giant litter, Mayer played it solo and Kathy Griffin was disappointed Clay didn't knock her up.

In NY: Rehab must have worked because Kirsten Dunst looked happy, Jay-Z was thankful and Natalie Portman went walking with her Jesus-alike boyfriend.

Larry Birkhead left stepped out with a curvy blonde last night, at the Bud Select Official Kentucky Derby Eve Party at the InTouch parlor.

Four years ago, Larry met Anna Nicole Smith at a Kentucky Derby Party.

Creepy factor? A solid 8.5.

It was a frightening week in the Thirty Mile Zone! Mary Ann from "Gilligan's Island" was busted with someone else's Mary Jane, Patricia Heaton gave up her belly button for Lint, Angelina put on a couple of baby lbs., Jocelyn "Catwoman" Wildenstein tried to frighten people away from plastic surgery and Angelyne gave us peek of what Paris will look like in the not-so-distant future. Click the pic to check 'em out!


Not scary enough? Take a peek at the pics from last week!

Recently named the sole heir of Anna Nicole Smith's Estate, Dannielynn Birkhead was driven strolled around downtown Studio City by her chauffeur (Daddy Larry) and nanny (Nanny).

Birkhead dropped a few Benjamins shopping at a local kid's store -- girl loves her clothes!