A police officer has been arrested on suspicion of misconduct in public office over the leak of information to national newspapers about former chief whip Andrew Mitchell's tirade at police officers on Downing Street, Scotland Yard said.

A police constable in the Diplomatic Protection Group was held yesterday evening and bailed today to return to police next month.

Mr Mitchell resigned in October after weeks of controversy over what he was supposed to have said to police after being told he could not ride his bike through the main gates.