Tom Griffin (London, OK): A bit of breaking news that's been inspiring a few rumours on the Tory blogosphere tonight. From PA:

A member of David Cameron's Tory frontbench team has been arrested, the party has disclosed.

Conservative immigration spokesman Damian Green, MP for Ashford in Kent, was arrested on Thursday afternoon at his home and taken for questioning at a central London police station.

He has not been charged with any offence.

In a statement, the Metropolitan Police said: "A 52-year-old man was arrested in Kent. He has been taken to a central London police station where he will be interviewed by detectives.

"The man has been arrested on suspicion of conspiring to commit misconduct in a public office and aiding and abetting, counselling or procuring misconduct in a public office."

The Telegraph adds more details:

It is claimed that nine counter-terrorism officers were involved in the arrest.

Mr Cameron has pledged his full support for the shadow immigration minister. In a statement he said: "Disclosure of this information was manifestly in the public interest. Mr Green denies any wrongdoing and stands by his action." 

Update: Mr Green has certainly obtained some interesting documents in recent months.  If the Government has uncovered a mole, it will be interesting to see how they are treated.

The track record is extremely varied in recent years. Leo O'Connor and David Keogh were jailed for two years for leaking details of a conversation in which George Bush told Tony Blair that he wantd to bomb Al-Jazeera television.

By contrast, Derek Pasquill was ultimately not prosecuted over his disclosures about CIA rendition flights and Government relations with Muslim groups because of an internal memo that said they had not been damaging.

Somehow, I can't see a similar email turning up in this case.