Former NBC late night host Jay Leno voiced his support on Wednesday for the women who have come forward claiming they were sexually assaulted by comedian Bill Cosby.

Leno, who stepped down as host of The Tonight Show last year, was asked at a National Association of Television Program Executives conference what he thought of the allegations against Cosby.

"I don't know why it's so hard to believe women. I mean, you go to Saudi Arabia and you need two women to testify against a man; here you need 25," he replied.

'I don't know why it's so hard to believe women. I mean, you go to Saudi Arabia and you need two women to testify against a man; here you need 25.' - Jay Leno

Over the last three months, more than a dozen women have come forward alleging that Cosby had sexually abused them. Many of those allegations are decades old and fall outside the statute of limitations for criminal or civil cases.

Cosby's attorney Marty Singer has dismissed the allegations as "discredited" and "defamatory."

At Wednesday's conference, Leno added that he supported the way the allegations against Cosby were brought into the spotlight, after standup comedian Hannibal Buress called Cosby a rapist during a performance last October.

"He made a flat-out statement that reverberated around the world. If that was on TV, it would have been edited. If it were on any other medium, it would have been edited," Leno said.

"But because somebody just filmed it and put it out there, you're getting your news raw and unfiltered, which I think is fantastic."

Many refunds for Cosby's Denver shows

Leno's comments come after actor Malcolm-Jamal Warner, who played Cosby's son on television, told music trade magazine Billboard that he found it painful to hear the claims that the comedian sexually abused more than a dozen women.

Warner, who played Theo Huxtable on The Cosby Show in the 1980s and 1990s, said the allegations do not match Cosby's reputation.

"The Bill Cosby I know has been great to me and great for a lot of people," Warner was quoted as saying.

"Just as it's painful to hear any woman talk about sexual assault, whether true or not, it's just as painful to watch my friend and mentor go through this."

The 44-year-old Warner joined Cosby Show actors Phylicia Rashad and Keshia Knight Pulliam in defending the 77-year-old comedian.

Meanwhile, the Associated Press reported that nearly 40 per cent of the tickets originally purchased for Bill Cosby's two comedy shows in the Denver earlier this week were refunded, according to an official for the company that runs the venue.

According to his website, Cosby next performs Jan. 30 in Sandusky, Ohio, with a pair of Feb. 8 shows scheduled in Boston.

With files from The Associated Press