The CBI was on the brink of collapse on Friday as many of the biggest names in British business cancelled their memberships after a second woman alleged she had been raped while working at the UK employers’ organisation.

Aviva, Jaguar Land Rover, John Lewis, Virgin Media O2, WPP, ITV, Sage and Kingfisher all said they had quit the group. International companies including EY, BMW and Mastercard also cut ties.

The exodus came after The Guardian newspaper reported the allegation of rape, the second such allegation this month. The CBI has also been rocked by claims of sexual harassment, drug-taking and bullying.

For almost six decades, the CBI has been the premier lobbying organisation for business in the UK, sometimes working closely with government on policy and sometimes clashing, notably when it strongly opposed Britain’s exit from the EU.

The CBI board met on Friday to discuss the latest findings from an internal probe even as the departing members threatened to make the organisation unviable. Accenture, a large sponsor of last year’s annual CBI conference, was among those to sever ties on Friday evening.

FTSE 100 insurer Aviva said: “In light of the very serious allegations made, and the CBI’s handling of the process and response, we believe the CBI is no longer able to fulfil its core function — to be a representative voice of business in the UK.”

The company added it was “regrettably” ending its membership “with immediate effect” — a statement echoed by John Lewis, the Association of British Insurers and Lloyd’s of London.

The CBI on Thursday had said it had been passed information about a serious crime and was now “liaising closely” with the police.

The Guardian reported on Friday that a rape had taken place at one of the CBI’s overseas offices, but declined to specify the date of the incident or the country where it took place in order to protect the alleged victim’s identity.

The City of London Police is already investigating an allegation of rape at a 2019 CBI staff party on a boat on the river Thames, alongside other allegations of misconduct made by a dozen people who have worked at the organisation.

The City of London Police confirmed its investigations “regarding sexual misconduct at the CBI” continued, adding that “at the present time there have been no arrests made”.

A independent investigation at the CBI’s request by Fox Williams, the law firm, has led to the suspension of three staff. The CBI has said it expects to publish the probe’s conclusions early next week.

The group separately fired its former director-general Tony Danker this month for unrelated workplace misconduct. Danker said this week he had been made the “fall guy” for the much more serious allegations.

The Guardian report included graphic details of the second alleged rape, which the woman involved said took place at the hands of two men after a night of heavy drinking.

The woman said she had no recollection of the rape itself, but had described in detail the physical signs that led her to believe she was raped and was later presented in the office with an explicit photograph related to the incident.

The woman told The Guardian she blamed the CBI for allowing an atmosphere in which such incidents could take place and for failing to provide adequate human resources support.

CBI president Brian McBride said the new allegations were “abhorrent” and that the organisation had not been previously aware of them. “It is vital that they are thoroughly investigated now and we are liaising closely with the police to help ensure any perpetrators are brought to justice,” he added.

Additional reporting by Rafe Uddin, Judith Evans, David Sheppard, Laura Onita, Owen Walker, Anna Gross, Oliver Barnes, Michael O’Dwyer and Tim Bradshaw