Sky News understands the MP was accused by a young woman who works in parliament.
A former Tory minister has been arrested on suspicion of rape.
Sky News understands the MP was accused by a young woman who used to work in parliament.
He was arrested and taken to an east London police station on Saturday morning and was released on bail on Saturday night.
A police statement said: “The Metropolitan Police Service received allegations relating to four separate incidents involving allegations of sexual offences and assault.
“These offences are alleged to have occurred at addresses in Westminster, Lambeth and Hackney between July 2019 and January 2020.
“The Met has launched an investigation into the allegations.
“A man in his 50s was arrested on Saturday 1 August on suspicion of rape.”
The story first appeared in The Sunday Times.
Sky News understands the woman’s complaint was reported to a fellow MP.
It is claimed that some allegations were raised with the chief whip Mark Spencer and with Jacob Rees-Mogg, the leader of the House of Commons some weeks ago.
It has been reported that Mr Spencer had not known the “magnitude” of the allegations.
It’s understood Mr Spencer told the woman to make a formal complaint to parliamentary authorities, who would investigate.
She later went to police.
Housing Secretary Robert Jenrick told Times Radio: “These are very serious allegations and they should be investigated.
“I know this is being handled by the chief whip, who is in contact with the Member of Parliament in question and I’m sure they’ll take all the steps that are required as further information comes to light.”
A Conservative Party statement said: “We take all allegations of this nature extremely seriously. As this matter is now in the hands of the police it would be inappropriate to comment further.”
A statement from Mr Spencer said: “The chief whip takes all allegations of harassment and abuse extremely seriously and has strongly encouraged anybody who has approached him to contact the appropriate authorities, including parliament’s independent complaints and grievance scheme, which can formally carry out independent and confidential investigations.”