A former lawyer for a large U.S. law firm pleaded guilty on Monday to conspiring to launder almost $19 million for his onetime client Kenneth Starr, a money manager known for representing celebrities.

Jonathan Bristol, 55, who once practiced at Winston & Strawn LLP, admitted that he used attorney trust accounts to help Starr launder money that he had taken fraudulently from clients.

Manhattan federal prosecutors also said Starr used these accounts to purchase a luxury apartment in New York.

Attorneys are supposed to promote respect for the rule of law, U.S. Attorney Preet Bharara said in a statement. Jonathan Bristol abused his position as a partner at a prominent New York City law firm to break the law over and over again.

Susan Kellman, a lawyer for Bristol, did not immediately return a call seeking comment. A spokesman for Winston & Strawn also did not immediately return a call.

Bristol pleaded guilty to one count of conspiracy to launder money in a hearing before U.S. District Judge Deborah Batts in Manhattan federal court.

He faces a maximum of five years in prison, and also agreed to pay $18.9 million in restitution.

Starr, whose clients included film director Martin Scorsese and singer Carly Simon, pleaded guilty in September to committing wire fraud, money laundering and adviser fraud. He was sentenced to 7-1/2 years in prison in March.

Starr is not the same Ken Starr who led the investigation of then President Bill Clinton in the affair over White House intern Monica Lewinsky.

The case is U.S. v. Bristol, U.S. District Court, Southern District of New York (Manhattan), No. 10-01239.

(Reporting by Carlyn Kolker in New York; Editing by Tim Dobbyn)