Phillip Schofield has been disciplined by ITV for passing a list of alleged paedophiles to Prime Minister David Cameron in a live stunt on This Morning, the programme of which he is a presenter, last week.

Ofcom, the media watchdog, announced they are launching an inquiry into the incident - in which Schofield ambushed the Prime Minister and asked what, if anything, he was going to do about the information he was just then being given.

Ofcom also announced an inquiry into the false allegations against Tory peer Lord MacAlpine broadcast by the BBC's Newsnight.

Ofcom will investigate whether the BBC and ITV “maintained appropriate standards” and ensured their programmes complied with broadcasting rules.

Schofield apologised personally on the day of his stunt, saying it was an error of judgement. The angle at which he passed the document to the Prime Minister meant some of the names were picked by a studio camera. Rumours immediately swirled around the internet and social media, with fears that the existence of the names in the public domain could lead to hysteria.

“If any viewer was able to identify anyone listed, I would like to apologise and stress that was never my intention”, Schofield said last week. “I was not accusing anyone of anything and it is essential that it is understood that I would never be part of any kind of witch hunt.”

“Unfortunately there may have been a misjudged camera angle for a split second as I showed the Prime Minister some information I had obtained from the internet. I asked for his reaction to give him the opportunity to make a point which he very clearly made about the dangers of any witch hunt.”

Schofield boasted that he had obtained the names in just three minutes of research on the internet. A spokesman for ITV today said: “Last Thursday we began an investigation into the circumstances surrounding the mistake on that day's This Morning programme, for which both Phillip Schofield and ITV apologised. This investigation has now concluded and the appropriate disciplinary action has been taken.

“We sincerely apologise because the way in which the issue was raised was clearly wrong and should have been handled differently. We have taken steps to make sure our editorial processes are always properly followed, which was not the case in this instance, and to ensure such an error will not be made again.“

No staff are thought to have been sacked over the incident, which led to Ofcom receiving 415 complaints. Schofield presented today's show as usual.