BBC and victim apologise to Lord McAlpine after admitting abuse claims were a case of mistaken identity

Another crisis for Newsnight as allegations emerge that victim who named Tory MP never saw a recent picture of ‘attacker’

Mr Messham offered "sincere and humble apologies" to Lord McAlpine and his family (Getty Images)

BBC's Newsnight was facing a fresh crisis last night after a victim of the North Wales care home scandal admitted he had misidentified Tory peer Lord McAlpine as taking part in abuse.

The programme apologised "unreservedly" last night for broadcasting the report, and announced the cancellation of all current Newsnight investigations.

It is claimed that reporters from the programme, which is already the subject of an internal investigation over its decision to drop a previous investigation into Sir Jimmy Savile, failed to show Steve Messham a recent photograph of the former Tory party treasurer. Furthermore, Newsnight did not put the allegations to Lord McAlpine before broadcasting them.

In an apology broadcast on last night's programme, Newsnight said: "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 well as suspending all Newsnight investigations for editorial "robustness" to be assessed, the BBC's Director General, George Entwhistle, sent a senior news executive to supervise last night's show, ordered an urgent report on the care home investigation and suspended all co-productions with the Bureau of Investigative Journalism across the BBC.

The apparent journalistic failings came in advance of a report on the programme last Friday that carried the allegation that a senior unnamed Tory from the Thatcher era had been involved in abusing children at the home. The segment did not name the Tory for legal reasons, but Lord McAlpine's name was subsequently circulated on the internet. The BBC had defended its investigation as in the public interest.

But in what could be a devastating blow to the credibility of the programme, Mr Messham last night offered his "sincere and humble apologies to him [Lord McAlpine] and his family". He said: "After seeing a picture in the past hour of the individual concerned, this [is] not the person I identified by photograph presented to me by the police in the early 1990s, who told me the man in the photograph was Lord McAlpine."

Tory grandee Lord McAlpine warned he was preparing legal action after issuing a statement denying internet claims and media innuendo that he had sexually abused young people in Bryn Estyn care home in Wrexham. Lord McAlpine, 70, who is in ill health and lives in Italy, volunteered to return to Britain to answer police questions on the allegations, which he described as "wholly false and defamatory".

Speculation has raged on the internet for days following the Newsnight broadcast last Friday. A number of high-profile figures, including Sally Bercow, the wife of Commons Speaker John Bercow, had referred to him on Twitter. Environmentalist George Monbiot also yesterday apologised for posts that "contributed to [the] febrile atmosphere".

Lord McAlpine said in a statement: "I must publicly tackle these slurs and set the record straight. It is obvious that there must be a substantial number of people who saw that I had been identified in the internet publications as this guilty man and who subsequently saw or heard the broadcasts or read the newspapers in question and reasonably inferred that the allegation of guilt in those broadcasts and newspapers attached to me."

Lord McAlpine said that he had sympathy for his accuser: "I wish to make it clear that I do not suggest that Mr Messham is malicious in making the allegations of sexual abuse about me. He is referring to a terrible period of his life in the 1970s or 1980s and what happened to him will have affected him ever since." Lord McAlpine said he had been to Wrexham only once when he visited the local constituency Conservative Association whilst deputy chairman, and that at all times he was accompanied by Conservative Central Office agent Stuart Newman, who has since died.

He also denied ever visiting the children's home or any other similar institution.