THREE Downing Street police officers arrested on suspicion of accessing "extreme" pornography on their mobile phones will not face criminal charges.

The constables of the SO6 Diplomatic Protection Group were arrested on December 19 and questioned at a London police station and their homes searched.

Yesterday, a spokesman said: "Three officers have been informed there will be no further action regarding criminal matters but they remain subject to a misconduct investigation."

A decision has yet to be made regarding a fourth officer about the images, which were of an "extreme sexual nature".