Andrew Mitchell is reportedly sceptical over Mr Hogan-Howe's involvement. Picture: David Jones/PA Wire

A man has been arrested and bailed in connection with the investigation into the Andrew Mitchell Downing Street row.

The 23-year-old was detained at 8pm last night on suspicion of intentionally encouraging or assisting the commission of an indictable offence and questioned at a London police station.

The suspect, who Scotland Yard said is not a police officer or member of police staff, is the second man to be arrested.

He was released on bail until a date next month.

The date of the alleged offence came a day after police received fresh information on a row - alleged to have taken place between Mr Mitchell and police officers at the Downing Street gates on September 19 - and one day before the officer was arrested.