A High Court Judge has criticised the Metropolitan Jolice for failing to adequately investigate allegations of phone hacking by the News of the World.

Mr Justice Vos made the comments at a pre-trial hearing for the legal actions by former Sky Sports commentator Andy Gray and actor Steve Coogan. They allege that the tabloid ordered private investigator Glenn Mulcaire to hack into their mobile phone voice messages.

"The Metropolitan Police had not done an appropriate job in analysing phone-hacking... information in their possession," Vos said. "They didn't disclose highly relevant information."

He added that Scotland Yard had failed to fully comply with court orders requiring it to produce copies of Mulcaire's notes relating to the two men.

The Met reopened its investigation last month after fresh evidence emerged about the extent of phone hacking at the paper.

Vos also criticised the News of the World for doing "absolutely nothing" to shed light on which journalists at the title might have worked with Mulcaire.

"They may have been hacking into Mr Gray's phone for months and months," he said. "I don't know. We just don't know the full extent of it."

He said the paper's publisher News Group, part of Rupert Murdoch's media empire, had failed to hand over any material, including reporters' notebooks, in the course of the police investigation.

News Group argued in court that the case bought by Gray and Coogan is "speculative" because it cannot be proved Mulcaire listened to voicemail messages belonging to either of them. The company concedes he made notes of their numbers and account details.

"To say the whole case is speculative is frankly nonsense... to say there is not a shred of evidence is going too far," Vos said.

He cited evidence handed by the Met to Gray which showed Mulcaire kept detailed notes of his mobile phone account number, pin number and password.

Vos said: "Give me one possible reason why Mr Mulcaire would have held those pieces of information for any other reason [than to hack into Gray's phone]."

Mulcaire was jailed for six months in January 2007 for illegally intercepting voicemail messages belonging to members of the royal household and several other well-known figures.

The paper's former royal editor Clive Goodman also received a shorter jail term after pleading guilty to the same charge.