British funnyman Ricky Gervais has backtracked over his criticism of Justin Bieber's Anne Frank blunder, insisting the teenage star is not "nasty" or "evil". The Office actor openly mocked the Baby singer after he hit headlines by writing a disrespectful comment in a guest book at the Anne Frank house museum in Amsterdam, Holland, suggesting the famed teenage diary writer, who died in the Holocaust, would have been a fan of his music. Gervais wrote, "I agree with Justin Bieber. Anne Frank would've loved his stuff. It's perfect for being played really really quietly so no one can hear it. 30 million illiterate teenage girls are now crying... and asking Google 'Who is this b**ody Anne woman that Justin likes so much?' Joan of Arc was a great girl. I hope she would have been a Gervatheist (sic)." However, Gervais has now ended his jibes and insisted the young star was just being "a prat" and should not be condemned for his mistake. He adds, "On a serious note: I think we should remember that Bieber wasn't being nasty. He's a prat, but not evil. Just a bit gimp." Anne Frank became one of the best-known Jewish victims of the Holocaust following the publication of her diary in 1947. She died at the age of 15 at the Bergen-Belsen concentration camp in Germany in 1945.