A review into the arrest of Ashford MP Damian Green has appeared to question aspects of the operation conducted by the Metropolitan Police.

The independent review was handed to the Met Police yesterday. It said the MP's arrest was lawful, but questioned the actions and methods.

Although it has not been published in full, the police issued a statement that is being seen as a clear signal that its inquiries may soon be dropped.

Mr Green was arrested on November 27 and his homes in Kent and London, as well as his parliamentary offices, searched by counter-terrorism police officers. The move came as part of an inquiry into a series of leaks from the Home Office.

In a statement yesterday, the assistant commissioner of specialist operations, Bob Quick, who led the inquiry into the leaks and made the decision to arrest Green, said: "He [Ian Johnston, who led the review] recognises that there are arguments, either way, regarding proportionality over the manner of arrest of a member of parliament, but questions the method taken in this case. He also raises concerns as to whether elements of the investigative approach meet current policy and best practice. These issues will be carefully considered."

The Met Police is now discussing with the Crown Prosecution Service about the best way forward.

A Conservative spokesman said: "As we have said all along, we believe Damian Green has done nothing wrong. This statement shows that there were very serious failings in the police operation against him."