'Serious questions' over MP's arrest, says Cameron

David Cameron insisted police and ministers had "serious questions" to answer today after one of his frontbench spokesmen was arrested over Home Office leaks.

The Tory leader hit out after shadow immigration minister Damian Green was held in custody for nine hours last night as part of a Scotland Yard investigation.

Mr Cameron said: "I think there are some serious questions that have to be answered. If they wanted to talk to Damian Green, why not pick up the telephone and ask to talk to him?"

Mr Cameron raised concerns that at least nine counter-terrorism officers had been deployed to detain Mr Green and search his house and Commons office.

"The police have to answer questions," he said. "Frankly, Government ministers have got questions to answer as well."

Mr Green, 52, MP for Ashford, expressed fury early today after he was questioned in connection with a series of confidential Home Office papers which have found their way into the public domain recently.

He was released on unconditional bail shortly before midnight without charge, but must return to face further questioning in February.

Speaking to reporters outside the House of Commons at about 12.45am today, he said: "I was astonished to have spent more than nine hours today under arrest for doing my job.

"I emphatically deny I have done anything wrong.

"I have many times made public information that the Government wanted to keep secret - information that the public has a right to know.

"In a democracy, opposition politicians have a duty to hold the Government to account. I was elected to the House of Commons precisely to do that and I certainly intend to continue doing so."

Downing Street and Labour have strongly denied that either Prime Minister Gordon Brown or other ministers had prior knowledge that the arrest was taking place.

The Metropolitan Police Service (MPS) released a statement last night insisting that the decision to arrest Mr Green at his home in Kent and transport him to Belgravia police station in central London for questioning was taken "solely by the MPS without any ministerial knowledge or approval".

Senior Tory sources have branded the operation "Stalinesque", and suggested police must have received authorisation from the very top of the Government.

Mayor of London Boris Johnson said he was informed of police plans in advance and voiced "grave" concerns to acting Met Commissioner Sir Paul Stephenson, warning him that he did not regard it as "commonsense policing".

Former shadow home secretary David Davis insisted the action was "somewhere between an astonishing error in judgment through to judicial intimidation".

Mr Davis, who quit the Tory front bench to campaign against the Government's erosion of civil liberties, said Mr Green had only been "doing his job".

He told BBC Radio 4's Today programme: "None of this put in any way national intelligence, national security, or international relations at risk - yet we end up with a situation that is in some way reminiscent of Robert Mugabe's Zimbabwe, with an opposition spokesman being arrested for nine hours.

"It is extraordinary, frankly."

Mr Davis said he found it "hard to believe" that ministers were not told that Mr Green was about to be arrested.

"I cannot believe it," Mr Davis said. "Why were they not told?"