Broadcasting watchdog Ofcom has launched an investigation into Frankie Boyle's show after Katie Price complained about a joke he made about her disabled son.
Price accused the comic of being a "bully" after he made comments about her son Harvey, who suffers from septo-optic dysplasia and autism, on his show Tramadol Nights.
A spokesman for Ofcom said: "We can confirm that we have received a complaint from Katie Price. Having considered this and other viewers' concerns, we have now launched an investigation into the show."
Price on Thursday announced that she had asked her lawyers to contact the watchdog if Channel 4 did not apologise.
A spokeswoman for the channel said: "Channel 4 has replied directly to Katie Price's lawyer. Given this has now gone to Ofcom it would be inappropriate for us to comment further."
In a statement put on her website, Price described her son as "a little miracle".
It continued: "If Mr Boyle had a 10th of his courage and decency he would know that to suggest, let alone think funny, that Harvey may sexually attack me is vile and deeply unfair. To bully this unbelievably brave child is despicable, to broadcast it on television is to show a complete and utter lack of judgment."
A message at the beginning of Boyle's programme, broadcast on Tuesday night, warned viewers the show contained "very strong language and uncompromising adult content".
It is not the first time the comedian's jokes have landed him in trouble. In April he had an on-stage argument with the mother of a Down's syndrome child after making fun of the condition, while in August 2008 he said Olympic swimmer Rebecca Adlington looked like "someone who's looking at themselves in the back of a spoon".
The Ofcom investigation is likely to consider whether the show broke sections of the Broadcasting Code about "generally accepted standards" of material which could be deemed offensive.