Lawyers for comedian Bill Cosby have asked a Pennsylvania court to dismiss sexual assault charges filed against the comedian late last month, saying prosecutors violated terms under which he gave a deposition in a civil lawsuit a decade ago.
Cosby, 78, was charged last month with sexually assaulting a woman in 2004 after plying her with drugs and alcohol.
The charges, filed days before the statute of limitations on the alleged crime was to expire, are the only criminal charges the entertainer faces after more than 50 women accused him of sex assault.
Defence lawyers on Monday (local time) asked a judge to disqualify Montgomery County, Pennsylvania, District Attorney Kevin Steele from prosecuting the case, noting that he had said during his recent election campaign that he would work to charge Cosby if elected. His rival in the race made similar comments.
Officials with the Montgomery County District Attorney's office could not be reached for immediate comment on Monday.
"The charges brought on December 30, 2015 violate an express agreement made by the Montgomery County District Attorney in 2005, in which the Commonwealth agreed that Mr Cosby would never be prosecuted with respect to the allegations of sexual assault made by complainant Andrea Constand," Cosby's lawyers said in a statement.
The deposition was given in a civil lawsuit against Cosby by Constand, now 44. That lawsuit was settled in 2006 for an undisclosed sum.
Cosby, who personified the model family man in his hit 1980s television series The Cosby Show, and his lawyers have acknowledged marital infidelity on his part but have denied any allegations of sexual misconduct.
Cosby is free on US$1 million bail and his lawyer has said he is not guilty and will not consider a plea bargain.
Prosecutors in California last week decided not to charge Cosby over sexual assault allegations made by two other women.
Earlier on Monday, George Washington University said it was rescinding Cosby's honorary doctorate over sexual assault allegations. The allegations have distressed alumni and students who have been sexually assaulted, it said.
USA Today newspaper reported last week that about 23 schools out of about 60 have rescinded Cosby's honorary degrees.
US politician Paul Gosar, an Arizona Republican, and several colleagues introduced a bill on Friday that would strip Cosby of his Presidential Medal of Freedom, the highest US civilian honour.