Los Angeles (AFP) - A California university has joined a growing number of schools in stripping disgraced US comedian Bill Cosby of his honorary degree over the sex scandal engulfing him.

"Cosby's conduct is contrary to the values of the California State University and inconsistent with the criteria and high standards that honorary degree recipients are expected to exemplify," the university said in a statement.

"The CSU has been awarding honorary doctorate degrees since 1963, and this is the first time in 52 years that the Board of Trustees has voted to rescind a degree."

It said the board voted on the measure Wednesday.

Cosby, once one of America's most beloved actors, has seen his reputation destroyed as some 50 women have come forward to accuse him of sexual assault.

Last week, two other universities -- Drexel in Philadelphia and Bryant in Rhode Island -- rescinded honorary degrees awarded to Cosby.

CSU said it had decided to follow suit in order to uphold the institution's high standards and reputation.

"The board took action to revoke the previously awarded honorary degree in order to maintain the prestige, reputation and credibility of the CSU," it said.