ITV has said it has taken "appropriate disciplinary action" over the incident where This Morning presenter Phillip Schofield confronted David Cameron with a list of alleged paedophiles.
Phillip was roundly criticised earlier this month after he handed the Prime Minister a list of names - understood to be Conservative Party figures - during the live show which he said he had put together from internet rumours.
An ITV spokesman 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."
The presenter later had to apologise after the list was briefly exposed on screen.
After being handed the list, which Phillip assembled after trawling the internet for three minutes, the Prime Minister warned that online discussions of an alleged paedophile ring could degenerate into a "witch-hunt" against people who are gay.
Meanwhile, broadcasting watchdog Ofcom has launched investigations into This Morning and BBC's Newsnight after complaints the shows breached "generally accepted standards". The shows are also under scrutiny for "the application of standards to prevent unfair treatment to an individual, and unwarranted infringements of privacy".
The programmes are the November 2 Newsnight which wrongly implicated Lord McAlpine in a paedophile ring and the November 8 This Morning.
The BBC is thought likely to reach a financial settlement with Lord McAlpine on Thursday after apologising to the peer.