Richards launched a furious rant at two black hecklers during a standup show in Los Angeles last weekend.
At the request of pal Jerry Seinfeld, Richards later appeared via satellite on the David Letterman Show to apologise.
But he has now been accused of making anti-Jewish comments during a stand-up routine as well.
Richards allegedly lashed out at Jews during performance earlier this year, yelling at one audience member: "You're a f***ing Jew. Your people are the cause of Jesus dying."