A former Tory minister been arrested after a former parliamentary aide accused him of rape, sexual assault and coercive control, according to reports.
The Conservative MP, who has not been named, is alleged to have assaulted a woman and forced her to have sex, The Sunday Times reported.
The abuse allegedly took place during a relationship, the publication added.
The Metropolitan Police said it received allegations on Friday of sexual offences and assault relating to four separate incidents at addresses in London, including in Westminster, between July last year and January this year.
A spokesman for the Met said: "On Friday, 31 July, 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 on suspicion of rape and was taken to an east London police station, the force added.
He has now been released on bail to return on a date in mid-August.
The papers said the allegations were raised with Tory Chief Whip Mark Spencer, and the complainant also spoke to him – but no action was taken.
It is understood Mr Spencer advised her to make a formal complaint to the authorities who would be able to investigate the claims.
A spokesman for 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.”
A Conservative Party spokesman 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.”