The Conservative MP arrested on suspicion of rape and sexual assault offences has now been released on bail pending further enquiries by the Metropolitan Police.
Scotland Yard said the unnamed man in his 50s – also detained on suspicion of indecent assault, abuse of position of trust and misconduct in public office – was taken into custody on Tuesday.
In an updated statement on Wednesday, the force said he has “been bailed pending further enquiries to a date in mid-June”, adding: “An investigation is ongoing.”
Officers received a report about the MP in January 2020 relating to alleged sexual offences committed in London between 2002 and 2009.
The Conservatives’ chief whip Chris Heaton-Harris has urged the MP to stay away from parliament – but has not yet suspended the whip, meaning the suspect remains a member of the parliamentary party.
It was understood the Tories will not make a decision on whether the suspect has the whip suspended until after the police investigation is concluded.
The Prospect union, which represents hundreds of staff working in the parliament, said firmer action is needed.
Deputy general secretary Garry Graham said: “What will it take for parliament to finally take its responsibility to its staff and visitors seriously and suspend access to the estate for parliamentarians under investigation for sexual offences?”
Foreign Secretary Liz Truss said she was “very, very concerned” that a Tory colleague had been arrested – but would not be drawn on whether the whip should be removed.
Asked how she felt when she heard the news, she told Sky News: “I’m very, very concerned about the reports that I’ve heard. The police are currently working on the case but it is worrying that we are seeing these appalling … accusations, again, about a parliamentarian.”
Asked if the MP should have the whip withdrawn, Ms Truss said: “I don’t know who it is. I know that the police are looking at it and investigating it, and I think we need to wait for the police to conduct those investigations.”
The arrest comes amid renewed scrutiny of sleaze in Westminster following a string of cases. Former Conservative MP Imran Ahmad Khan quit the Commons earlier this month after being convicted of sexually assaulting a boy.
David Warburton had the Conservative whip withdrawn after allegations of sexual harassment and cocaine use emerged.
Over the last year, about 15 MPs are suspected to have been investigated by parliament’s Independent Complaints and Grievance Scheme (ICGS) watchdog that examines allegations of bullying, harassment or sexual misconduct.
Neil Parish stood down as the Conservative MP for Tiverton and Honiton earlier this month after admitting watching pornography in the Commons.
The latest arrest also follows a Tory MP being arrested on suspicion of rape in 2020. He was never identified and police took no further action after an investigation.
Conservative sources declined to identify the individual arrested on Tuesday, citing the need to protect the identity of any complainant.
A statement from the Tory whips’ office said: “The chief whip has asked that the MP concerned does not attend the parliamentary estate while an investigation is ongoing. Until the conclusion of the investigation we will not be commenting further.”