Bill Cosby's biographer has apologised for leaving details about the comedian's alleged sexual abuse out of his book Cosby: His Life and Times.

Mark Whitaker took to Twitter.com on Monday (24Nov14) and admitted he was "wrong" for not including allegations about the comic.

His apology comes hours after New York Times reporter David Carr criticised Whitaker for ignoring the allegations in his recent book, suggesting the biographer should have investigated fresh claims against his subject.

Whitaker wrote, "David, you are right. I was wrong to not deal with the sexual assault charges against Cosby and pursue them more aggressively."

He added he has been following "new developments" and "will address them at the appropriate time". He tweeted, "If true, the stories are shocking and horrible."

Whitaker's tome was released in September (14).

Cosby has been hit with a number of decades-old abuse allegations in recent weeks, following a much-publicised stand-up routine, in which comic Hannibal Buress called the star a "rapist".

Cosby's attorney, Marty Singer, has dismissed the claims against his client, who is fighting to keep a current tour on track following the cancellation of a handful of dates. Promoters fear theatre fans will boycott venues if Cosby shows proceed.