Coulson faces arrest as police say up to 4,000 were hacked

Andy Coulson, the former editor of the News of the World, is about to become the highest-profile journalist to be arrested in the phone-hacking scandal, according to reports last night.

As police admitted that almost 4,000 people may have had their phones hacked by the News of the World, speculation was mounting that Mr Coulson would be formally arrested by officers from Scotland Yard today.

According to reports, which The Independent could not verify last night, detectives contacted Mr Coulson yesterday and asked him to present himself at a police station in central London, where he will be formally questioned under suspicion of involvement in hacking. A second as yet unidentified former senior journalist at the NOTW is also expected to be arrested in the next few days, according to the newspaper.

The arrest of Mr Coulson – who has always denied any involvement in hacking – comes six months after he left Downing Street, where he was the communications director for David Cameron.

Police are thought to have speeded up their plans to arrest the suspects after leaks from News International, which owns the News of the World and The Times, which reported there would be shortly further arrests.

The arrests will be carried out by officers from Operation Weeting, whose leading investigating officer, Deputy Assistant Commissioner Sue Akers, warned there were almost 4,000 likely victims of the private investigator Glenn Mulcaire, who was exclusively contracted to the NOTW.

The estimate sharply contrasts with the evidence given by Andy Hayman, the officer who led the original investigation into Mr Mulcaire's activities in 2006-07 who said that there were "perhaps a handful" of hacking victims.

After reviewing the first inquiry and finding it to have been properly conducted, Assistant Commissioner John Yates told the Home Affairs Select Committee in September 2010: "We can only prove a crime against a very small number of people and that number is about 10 to 12 people. That is very few people."

As it acknowledged the true scale of the wrongdoing, Scotland Yard stated that it would be inappropriate for it to investigate new allegations that the News of the World had bribed police officers for sensitive information. Corrupt officers are thought to have been paid more than £100,000 each for passing the tabloid sensitive information.

The Met initially said this week that could it could investigate the case. Yesterday, it said that public disapproval had led it to hand the investigation to the Independent Police Complaints Commission.

Ms Akers, who will appear before the Home Affairs Select Committee on Tuesday, said: "We recognised the gravity of this case from the outset and involved the IPCC at the first opportunity. I strongly believe in and welcome independent oversight, especially in a case such as this, where public confidence in the police is seriously at risk."