Tory fury over arrest | Analysis: a warning to moles | Blog: the most sinister law in the system? | Profile: Damian Green

The fallout from the arrest of Tory frontbencher Damian Green deepened this lunchtime as it emerged the Conservatives filmed the police raid on his office.

The Times has discovered the party has video footage of police going through files in the immigration spokesman's office in the Palace of Westminster, a raid which has sparked outrage amond MPs from all sides of the House.

This is likely to put greater pressure on the Speaker and House authorities to justify why they allowed police into an MP's office. So far the Speaker's office has told Douglas Carswell, a fellow Conservative MP, "there is a process to be followed that was followed".

The party is preparing to issue a list of up to 40 questions about the conduct of the police, Parliamentary authorities, the Home Office and ministers.

Mr Green is at the centre of allegations that he received a series of leaks from a Home Office official which later appeared in he press. He denies wrongdoing and has been bailed by police until February. Any prosecution would hinge on whether it could be proved he "actively encouraged" the official to break the law.

The Times understands a Home Office employee was arrested at dawn on November 19. Sources suggest the individual was an Assistant Private Secretary who, under a security lapse, had access to more than one private office

David Cameron's office were given a few minutes notice that the lunchtime raid in Mr Green's Portcullis House office was due to take place. However, they were not allowed to observe the search at close quarters.

"There was no question that the police wanted to allow anyone to be there", said a source who said the Tories were prevented from having a "permanent presence" at the scene while the raid was going on.

Files are believed to have been taken away from Mr Green's Commons office, along with material from his home in Kent. His BlackBerry and mobile phone were also confiscated, along with paper and electronic files.

Mr Green, the party's immigration spokesman, was arrested at his Kent home at 1.50pm yesterday and driven to central London. He was released around 10.40pm and questioned twice.

Conservative members of the Home Affairs Select Committee are preparing to demand an investigation into the circumstances of Mr Green's arrest, including the involvement of Parliamentary authorities.

The Tories believe the Sergeant at Arms, whose office overseas Commons security, was contacted by the police. The Sergeant contacted Michael Martin, the Speaker's office, who "did not raise objections" to a raid going ahead.

The Tories are suspicious because Parliament is currently prorogued, before the new Parliamentary year begins with the Queen's Speech on Wednesday.

David Normington, the Home Office Permanent Secretary, has said ministers were unaware of police involvement. He called in officers to investigate leak allegations himself, and claimed ministers only knew of the arrest of Mr Green after it happened.

Times Recommends

• Foxy Knoxy snared by her lust and her lies
• Britain is the land of the shrinking family
• Zac Goldsmith: Not such a green god