Scotland Yard has lost crucial documents which would have disclosed whether the former Commissioner of the Metropolitan Police, Lord Stevens, frequently met senior News of the World executives while he was in office, including an editor at the tabloid who is alleged to have been involved in the illegal hacking of emails.

The Information Commissioner's Office (ICO) confirmed to The Independent that it is currently investigating the missing diaries of the former Commissioner.

In response to a Freedom of Information request made by Ian Hurst, a former British Army intelligence officer who was involved in running IRA informers in Northern Ireland, the Met said that its officers had been "unable to locate the diary of Lord Stevens and cannot therefore answer your questions in relation to him".

Mr Hurst, who is a "core participant" in the Leveson Inquiry that will examine illegal practices at Rupert Murdoch's News International, asked the Met whether two former Commissioners, Lord Stevens and Sir Ian Blair, had held meetings with Alex Marunchak, a former editor of the NOTW's Ireland edition, between 2000 and 2011.

The Met said there were no recorded meetings with Sir Ian – but that Lord Stevens' appointments diary could no longer be located.

Mr Marunchak, who left NI in 2006, denied allegations in a BBC Panorama programme broadcast in March this year that he paid a private detective to hack into emails on Mr Hurst's computer. The BBC film showed footage of a meeting between Mr Hurst and a former Army intelligence colleague who claimed he had accessed the emails under instruction from Mr Marunchak. Mr Hurst is suing the NOTW, alleging that the newspaper employed private detectives to hack into his computer and obtain information relating to his handling of a senior IRA informer.

The ICO confirmed that the missing diaries cover the period 2000 to 2005 when Lord Stevens was head of the Met. During this period he conducted an external police inquiry in Northern Ireland that concluded there had been collusion between the British Army, the Royal Ulster Constabulary and loyalist terrorists that had led to the murder of nationalists in the province.

One colleague of Lord Stevens during his time as head of the Met described him as "a master" of dealing with the media, and said he cultivated associations with Fleet Street's editors. The Home Secretary, Theresa May, later said she had concerns over the closeness of the relationship between News International and the police. Officials investigating the disappearance of the diaries will have to decide if there has been a breach of the Data Protection Act.

The is the first time the ICO has had to deal with such a high-profile disappearance from what should be a public archive.

A spokesman for Lord Stevens said last night: "The diaries of the Metropolitan Police Commissioner are the property of the Metropolitan Police and therefore they must be approached for that information."

The Metropolitan Police, however, said that Lord Stevens' diaries were not a public document, and added that "there is no requirement to keep the dairy of the outgoing Commissioner, which is a working document to support the running of the office on a daily basis".

How 'Captain Beaujolais' became a master of the media

Lord Stevens

During his time as head of the Met, from 2000 to 2005, John Stevens' colleagues noted his fondness for fine wine: he became "Captain Beaujolais". He also divided their loyalty. For some he was "a copper's copper", the man responsible for a rise in the number of officers and improved crime figures. Others noted the charm offensive deployed on Fleet Street, aided by the Met's public affairs head, Dick Fedorcio.

One senior officer said he was "a master of the media" who hadn't appreciated the costs attached to close media relationships.

After he left the force, his police experience delivered significant wealth: he is the executive chairman of Quest Ltd, a corporate security business, and holds four other directorships. His links to the media were maintained. A column for the NOTW saw Captain Beaujolais put to one side in favour of "The Chief". The NOTW's closure saw the chief's demise.