Updated 12.21

THE BBC HAS issued an unreserved apology to Lord McAlpine for a Newsnight report which led to him being wrongly implicated in the alleged sexual abuse of children at north Wales care homes.

A statement issued last night said, “On 2 November, Newsnight broadcast a report that looked into criticism of the North Wales Abuse Tribunal.

“The report included an interview with Steve Messham, an abuse victim who said that a senior political figure of the time had abused him.

“We broadcast Mr Messham’s claim but did not identify the individual concerned. Mr Messham has tonight made a statement that makes clear he wrongly identified his abuser and has apologised.

“We also apologise unreservedly for having broadcast this report.”

As a result of the false report, Newsnight investigations have been put on an “immediate pause”. A supervisor was also sent into last night’s programme, during which a copy of the apology was issued. Director Ken MacQuarrie has ordered a serious inquiry as to what happened.

Lord McAlpine called Steve Messham’s claims “wholly false and seriously defamatory”. His lawyer threatened legal action against any of those who named him after the Newsnight report and linked him to abuse allegations.

Messham also apologised to the former Tory treasurer. He explained that in the 1990′s he was shown a photograph by police of his abuser and was incorrectly told it was Lord McAlpine. It was only on Friday, when he was shown a different photo, did he realise it was not the accused. By that point, McAlpine’s name had already been floated on Twitter.

Although BBC director general George Entwistle said the programme should not have aired, he noted the film itself did not make a named allegation.

“It’s no kind of excuse or exoneration,” he added. The show had repeated the claims against a 1980s politicians but did not name him. Twitter users did.

The editor-in-chief said he was not aware of the programme until after it was broadcast.

“We should not have put out a film that was so fundamentally wrong,” he told BBC’s Radio 4. “What happened here is so totally unacceptable. In my view the film should not have gone out.”

He has asked for MacQuarrie’s report to be submitted tomorrow.

“This was a piece of journalism referred to senior figures within News, referred up to the level of the management board and had appropriate attention from the lawyers,” Entwistle said.

“The question is, in spite of all that, why did it go wrong? Something definitely went wrong, something definitely and clearly and unambiguously went wrong.”

Meanwhile, the BBC Trust said it expects appropriate action to be taken.

UK broadcasters warned over “witch hunt”