BBC's press office have released a statement saying they apologise "unreservedly" for their Newsnight report:
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.