LOS ANGELES - One of the men who claims to be the father of Anna Nicole Smith's baby is splitting with the high-profile Beverly Hills attorney who has been representing him in the case.

Larry Birkhead and Debra Opri "have terminated our attorney-client relationship effective immediately," Opri said in a statement Friday.

"I wish Larry the very best of luck in his continuing efforts to prove that he is Dannielynn's biological father. My prayers will be with Larry and Dannielynn always," Opri said.

There was no word on who will replace Opri. She didn't indicate why she was leaving.

Calls to Opri and a representative for Birkhead weren't immediately returned Friday.

Attorney Howard K. Stern, who was living with Smith at the time of her death, is listed on the birth certificate as 6-month-old Dannielynn's father. He and the girl are living in the Bahamas.

Birkhead, Smith's former boyfriend, claims he is the father, and Opri has been vocal in demanding publicly that Stern come to California to take a paternity test to resolve the matter.

"Put up or shut up, that's what we're asking for," Opri said following a closed court hearing on the matter Tuesday.

Smith, 39, died of unknown causes Feb. 8 after collapsing at a Florida hotel.

Frederic von Anhalt, the husband of Zsa Zsa Gabor, also says he may be Dannielynn's father.