After begging forgiveness for a series of anti-gay remarks, US comedian Tracy Morgan is under fire from disabled groups for joking about “retards”.

The 30 Rock star performed a gig in New York on Saturday, his first since the now-infamous Nashville gig where he said he would stab his own son if he came out as gay.

Morgan apparently steered clear of anti-gay material in New York, but reports say he

He allegedly said: “Don’t ever mess with women who have retarded kids… Them young retarded males is strong. They’re strong like chimps!”

In another remark, he talked about having sex with a “cripple” ex-girlfriend.

The chief executive of disabled charity The ARC, Peter Berns, told E! News: “Tracy Morgan should apologise immediately. This quote is far too offensive to be excused as comedy, and it is very hurtful to people with intellectual and developmental disabilities and their families.

He added: “Mr Morgan has an incredibly powerful platform from which to fix this, and if he’s learned anything in the last few weeks, he can’t bomb this apology.”

After the Nashville gig, the comic visited a New York shelter to meet homeless LGBT teens.

He said: “I want to apologise to my friends, and my family and my fans and everyone in every community who were offended with this. I didn’t know. I didn’t mean it… I don’t have a hateful bone in my body. I don’t believe that anyone should be bullied or just made to feel bad about who they are.