John Yates's confession prompts calls for him to step down

One of Scotland Yard's top officers was urged to resign yesterday after admitting he had appallingly mishandled a review of the initial bungled investigation into phone hacking.

Assistant Commissioner John Yates, who reviewed the 2007 investigation in the space of a few hours two years ago and found it to be satisfactory, issued a grovelling public apology about his choice to resist calls to reopen the original investigation. He described it as a "pretty crap" decision, which he now "deeply regretted".

Conceding that the phone-hacking scandal had left the Metropolitan Police's reputation "very damaged", Mr Yates seemed to admit he had failed to perform his duties properly. He appeared to indicate that he had not inspected the 11,000 pages of notes seized from the News of the World's (NOTW) private investigator Glenn Mulcaire, which the Yard admitted last week contains evidence that he targeted almost 4,000 people, before making his decision.

Mr Yates told a Sunday newspaper: "I didn't do a review. Had I known then what I know now – all bets are off. In hindsight there is a shed load of stuff in there I wish I'd known." He added: "I'm not going to go down and look at bin bags [containing the evidence]," but he did say that he had asked 10 officers to input the information in the notebooks into a computer system.

Chris Bryant MP, a persistent critic of Mr Yates's performance, said: "It is inconceivable that Yates could remain. He has told the Home Affairs Select Committee that there were very few victims, that they had all been contacted, that they had got in touch with all of the mobile-phone providers and none of these things is true. I don't see how anybody can have confidence in how he does his job."

The original investigation was led in 2006 by Andy Hayman, after it surfaced that the NOTW had hacked the phones of royal aides. Mr Hayman, who has since joined News International as a columnist for The Times, will appear before the Home Affairs Select Committee on Tuesday alongside his former deputy, Peter Clarke, to explain the failure of the first investigation.

Deputy Assistant Commissioner Sue Akers, who is leading the new investigation and who has criticised the original one, will also appear. In a letter to the committee sent last October, Mark Lewis, lawyer for the victims, claimed that Mr Yates and Mr Hayman feared the paper would expose affairs they were having with colleagues in the force.

"At the relevant time," the letter reads, "Mr Hayman had reason to fear that he was a target of Glenn Mulcaire and the News of the World.

"It became public knowledge that throughout the period of the investigation into voicemail hacking, Mr Hayman was involved in a controversial relationship with a woman who worked for the Independent Police Complaints Commission and was claiming expenses which were subsequently regarded as unusually high," Mr Lewis said. He added that Mr Yates was in a similar position after being involved in "a controversial relationship with a woman who worked for the Met press bureau".

In the letter, he also said the NOTW had become "too close" to the police and had even benefited from tips from the paper that he said may have been garnered through phone hacking.

He also noted that Mr Hayman would not have been appointed at The Times "if [Mr Hayman] had extended the scope of the investigation and prosecuted further".