Channel 4 breached broadcasting guidelines with jokes about Katie Price's son Harvey on its Frankie Boyle comedy show, the media regulator has ruled.
The watchdog received hundreds of complaints about the comments aired on the controversial series Tramadol Nights.
They included Boyle joking that Katie and her ex-husband Peter Andre didn't want to keep the model's disabled son, and were fighting each other over who would not gain custody.
Former glamour model Katie complained that the comments, broadcast in December last year, were discriminatory and offensive.
Channel 4 defended the comments, adding that its job was to champion and pioneer "distinctive voices in British comedy and bring them to a wider audience".
It said that viewers were given strong warnings about the show, which started at 10pm, an hour after the watershed. It said that the joke about custody was not about Harvey but "aimed clearly at Katie Price and Peter Andre, painting them as cynically exploiting a child in custody proceedings in the media."
But Ofcom said that any "intended satire in the two comments was ... obscured by their straightforward focus on Harvey Price and his disability."
It accepted that Price, Reid and Andre "have consciously exposed their and their children's lives to the media". But it said that this did not justify humour targeted at a child's expense.
Katie later criticised Ofcom for not forcing the broadcaster to air an apology and said Channel 4's role as official UK broadcaster of the 2012 Paralympics should be questioned in the light of the finding. She said: "I am amazed that Ofcom have not required, at the least, an apology to be broadcast."
Complaints about other sketches in the series were not upheld.