Larry Birkead Threatens to Sue Over Shocking New Book

Larry Birkhead is blasting back at reports he struck a secret deal with Howard K. Stern to share Anna Nicole Smith's millions.

Birkhead, the father of Anna Nicole's baby daughter Dannielynn, is vowing to sue over journalist Rita Cosby's bombshell new book, “Blonde Ambition,” about Anna Nicole's death.

Sources tell “Extra” that those who have seen the book say it's so explosive, it could “re-open the Anna Nicole Smith case.”

New York Daily News Gatecrasher Ben Widdicombe explained, “It's strongly believed that the book alleges Howard K. Stern and Larry Birkhead struck a secret, backroom deal for the purpose of getting their hands on that money that Dannielynn may be owed from Anna Nicole's late husband.”

Today, “Extra” has Howard's side of the story, straight from a deep insider.

Top Hollywood private eye John Nazarian, Howard's personal P.I., insists there is no backroom deal between Howard and Larry.

He said, “I will go on the record. I know bad people. I'm a former policeman. And Howard and Larry are decent human beings just trying to raise a child.”

Nazarian admits that Larry and Howard are involved in Anna Nicole's estate, saying, “There's no secret there. They are protecting Dannielynn and doing what's appropriate.”

But the scandalous allegations from the upcoming book have already wreaked havoc.

OK! magazine has dropped Larry and Dannielynn from an upcoming cover, despite Larry telling the New York Daily News, “None of it's true.”

And while Howard lives an under-the-radar life in the Bahamas, Larry is also threatening to sue his former lawyer, Debra Opri!

Larry believes Opri may have leaked confidential documents to Rita Cosby for the book.

“I think Larry is going to learn that one day everything is fine with the media and other times, they turn on you,” Nazarian said.