Dover's Labour MP Gwyn Prosser is surprised by the arrest of Ashford MP Damian Green.

The Conservative immigration spokesman and Ashford MP was arrested yesterday afternoon on suspicion of "conspiring to commit misconduct in a public office" and has now been released on bail.

His home in Charing and constituency office in Bethersden were searched as were his London home and Commons office after warrants were gained.

Mr Prosser said: “My first reaction was surprise. From the information we have so far it seems to me to be a disproportionately heavy action to the alleged offence.

“As general rule if an MP receives information from a government department which he or she thinks is in public interest then indeed he or she should publish it. An MP has a duty to do this.

“On other hand if an MP colludes or conspires with a civil servant in order to solicit private and secret correspondence then that is very serious because the individual is encouraged to break civil service rules on privacy and confidentiality.

“At the moment it is too soon to know whether any of these categories apply in this case.”

Conservative leader David Cameron is angry about the arrest, describing it as "extraordinary".

He said: "There were nine counter-terrorism police officers in his house. There were police in the House of Commons.

"If they wanted to talk to Damian Green, why not pick up the telephone and ask to talk to him?"

Prime Minister Gordon Brown has denied any government knowledge of the arrest prior to it being made.

He said: "This is an independent police decision, it's an independent police investigation and the police have made it clear there was no ministerial involvement in this."

Mr Green has been bailed to re-appear before police next February.

The arrest is connected to four alleged leaks of information from the Home Office.