Lord Sewel has been suspended from the Labour Party following allegations that he took drugs with prostitutes.
The peer remained a member of the party despite giving up the whip under parliamentary conventions when he became deputy speaker of the Lords.
Scotland Yard has been called in to investigate the former minister after The Sun on Sunday published video allegedly showing him snorting cocaine while romping naked with two women.
An investigation by the House of Lords' sleaze watchdog that could lead to his expulsion from Parliament is also expected to be launched.
A Labour spokesman said: "Lord Sewel has been suspended from the Labour Party."