Scotland Yard said today: “A man was arrested on suspicion of indecent assault, sexual assault, rape, abuse of a position of trust and misconduct in a public office.”
The Met said the alleged sexual offences were committed between 2002 and 2009 in London.
They first received a report of the allegations in January 2020 and have conducted a two-year probe into the claims.
The unnamed MP faces suspension from the party while detectives from the Central Specialist Crime unit investigate.
Chief Whip Chris Heaton Harris has asked the MP to stay away from Parliament during the probe.