Bill Cosby's sexual assault trial has ended without a verdict after jurors failed to break a deadlock.

Jurors in Bill Cosby's sexual assault trial have asked for a definition of "reasonable doubt" on their fifth day of deliberations, a day after telling the judge they were deadlocked on all charges.

Jurors in the Bill Cosby sex assault case have adjourned after considering charges that could send the comedian to prison for the rest of his life.

A conviction could send Cosby, 79, to prison for the rest of his life.

Bill Cosby acknowledged to police more than a decade ago that he fondled Andrea Constand after giving her what he said were cold-and-allergy pills meant to help her relax, his sexual assault trial has heard.

Bill Cosby's chief accuser took the stand at his sexual assault trial to tell her story publicly for the first time, saying the comedian gave her pills that left her paralysed and helpless, before groping her.

Bill Cosby has also suggested racism "could be" behind the scores of accusations against him.

A sequestered jury from an outside county will decide the sexual assault case against Bill Cosby, a suburban Philadelphia judge has ruled.

A judge will let only one other accuser testify at Bill Cosby's sexual assault trial to bolster charges that the actor drugged and molested a woman at his estate near Philadelphia.

US entertainer Bill Cosby's lawyers are set to argue that prosecutors are reaching back to the "casting couch" era to round up female accusers and build a "stale" sexual assault case against him.

A judge refused to throw out the sexual assault case against Bill Cosby last night, sweeping aside claims that a previous district attorney had granted the comedian immunity from prosecution a decade ago.

Bill Cosby’s top legal adviser has said he never would have let the comedian testify in a 2005 lawsuit if he thought Cosby could still face sexual assault charges in the matter.

The former district attorney who declined a decade ago to bring sex-crime charges against Bill Cosby has testified that he believes his decision is binding on his successors and forever closes the door on prosecuting the comedian.

Bill Cosby’s lawyer has claimed that the sexual assault case against the comedian was politically motivated, brought by a newly-elected district attorney to make good on a campaign pledge.

Bill Cosby, 78, has filed legal papers against a woman accusing him of sexual assault, condemning her “obvious attempt to smear” him.

Bill Cosby, in sworn testimony a decade ago, said he had paid women after sex to keep the affairs from his wife, suggested he was skilled at understanding nonverbal cues for sexual consent and called one of his accusers a liar.

Another woman has come forward to claim that comedian Bill Cosby drugged and sexually assaulted her, it emerged today.