Bill Cosby -- I'm Not Talking About Rape Allegations

Bill Cosby says he will NOT talk about the old rape allegations that are making the rounds, but his mouthpiece is taking a clear stand ... the allegations were BS then, and they're BS now.

Cosby's lawyer says, "Over the last several weeks, decade-old, discredited allegations against Mr. Cosby have resurfaced. The fact that they are being repeated does not make them true."

As we previously reported ... Comedian Hannibal Buress called Cosby out last month during a stand up set -- wondering if people remembered Bill had been accused of rape by 13 women over the years.

The lawyer adds, "Mr. Cosby does not intend to dignify these allegations with any comment. He would like to thank all his fans for the outpouring of support and assure them that, at age 77, he is doing his best work."

During an NPR segment that aired this weekend an interviewer attempted to broach the subject with Cosby ... but he turned silent and shut the interview down.

The veteran comedian was also reportedly axed from an upcoming appearance on Letterman.