A Conservative MP has been released on bail after being arrested on suspicion of rape.
The Sunday Times reported that the allegations against the former minister were made by an ex-parliamentary employee.
The Met Police said the allegations relate to four separate incidents alleged to have taken place between July 2019 and January 2020.
The Conservative Party said it takes such allegations “extremely seriously”.
The Sunday Times, which first reported the story, said the complainant alleges that the MP assaulted her, forced her to have sex and left her so traumatised that she had to go to hospital.
The Metropolitan Police said it had launched an investigation into the allegations.
“On Friday, 31 July, the Metropolitan Police Service received allegations relating to four separate incidents involving allegations of sexual offences and assault,” the force said in a statement.
“These offences are alleged to have occurred at addresses in Westminster, Lambeth and Hackney between July 2019 and January 2020.
“A man in his 50s was arrested on Saturday 1 August on suspicion of rape. He has been released on bail to return on a date in mid-August.”
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.”
There are also reports that the Conservative Party’s chief whip, Mark Spencer, had been aware of allegations – and previously spoke with the alleged victim.
According to sources, Mr Spencer had not known the “magnitude” of the allegations.
A spokesman for the chief whip said that he took all allegations of harassment and abuse extremely seriously and had strongly encouraged anybody who has approached him to contact the appropriate authorities.