The head of the government’s ethics watchdog has stepped down after it was revealed he once admitted grabbing a colleague’s breasts in a police station.

Stuart Sterling, 48, was the first chief executive of the Ethics and Integrity Commission, set up by former Prime Minister Sir Keir Starmer last year to restore standards in public life.

But he quit this week pending an investigation when it emerged he was previously suspended from his job as a detective constable for sexual misconduct.

The disclosure is acutely embarrassing for the government as the commission was a key part of Labour’s mission to ‘reset’ and ‘clean up’ politics to ensure ‘the highest standards of integrity and honesty’.

Only last month Mr Sterling wrote that ‘standards should be a golden thread that runs through all public authorities’ He added that it was vital that ’employees are listened to when something doesn’t feel right and … confident that action will be taken’.

Northamptonshire Police is said to have considered criminal proceedings against Mr Sterling over the 2002 incident, but made the ‘wholly exceptional decision’ to let him return to his duties after he admitted wrongdoing.

However he was investigated over a second sexual misconduct claim six years later. He denied this incident and voluntarily left the force, but has refused to say if he was under investigation when he left. By then, the anti-corruption unit had made inquiries into the handling of the first probe.

Last night, Tory MP Greg Stafford told the Mail on Sunday: ‘These are very serious allegations which must be investigated with the utmost urgency.

Stuart Sterling has stepped down from the Ethics and Integrity Commission after it was revealed he once admitted grabbing a colleague’s breasts in a police station

‘If these claims are true, it raises very serious questions as to how Mr Sterling was appointed to his current role in the first place.’

A Cabinet Office spokesman said: ‘These are serious allegations. Stuart Sterling has stepped back from his role whilst we swiftly establish the facts.’

Key to the inquiry will be how the misconduct claims were missed during vetting and whether he gave an ‘appropriate and correct’ account of his past at relevant points.

When the commission was launched, former deputy leader Angela Rayner said it would take ‘swift, effective action at the first whiff of misconduct by ministers’.

In his role, Mr Sterling reported to the Prime Minister on standards in public life, providing recommendations on tackling misconduct and corruption.

Previously, he served in national security roles in the Cabinet Office and was seconded to the National Police Chiefs’ Council. He was appointed OBE by the King in 2023.

Whitehall’s due diligence processes are already under scrutiny after Lord Mandelson was appointed ambassador to the US despite warnings that he was a friend of paedophile Jeffrey Epstein and had ties to senior figures in China and Russia.

The Cabinet Office would not provide details of the checks it conducted before Mr Sterling joined the civil service, received an honour or was appointed to the ethics role.

The Sunday Times reported that, according to sources, in 2002, he and two fellow officers – one male, the other female – returned to the office at Corby police station after completing a routine patrol. Upon arrival in the report writing room, the female colleague –  a more senior colleague who was in her mid-thirties – removed her stab proof vest and placed it on the back of her chair.

At that point Mr Sterling, then aged 24, walked up to her from behind and placed two hands on her breasts. The male colleague objected, saying what he had done amounted to an ‘indecent assault’, and reported the matter to their superiors the same day.

Mr Sterling was immediately suspended on full pay. Leaked documents state the incident ‘resulted in consideration of criminal proceedings’. A person found guilty of indecently assaulting a woman faced up to ten years in prison at the time.

For reasons that remain unclear, the constabulary did not launch a criminal probe, opting instead for a ‘full misconduct hearing’. Documents describe a ‘serious incident [that] took place on police premises’ and which was to be handled as a case of sexual harassment.

According to police records, the force recognised that ‘such conduct would usually result in dismissal’. Yet, in March 2003, seven months after he was placed on leave, it instead imposed a financial penalty of two weeks’ pay – the maximum sanction short of forced resignation available at the time. 

The force claimed: ‘This was a wholly exceptional outcome, appropriate to the circumstances, which arose only due to the simultaneous occurrence of several issues’ – among them the fact that ‘guilt was admitted with openness and honesty’.

By 2008 he had been reported for sexual misconduct against another female colleague two years earlier. The incident allegedly occurred at a social gathering after a police shift. Sterling vigorously denied this incident ever took place.

A representative of Sterling said: ‘Stuart states that a full disciplinary process was held regarding the complaint in 2002, he complied with this fully. It resulted in a sanction.

‘He denies that the alleged incident in 2008 ever took place. He was never subject to any criminal investigation, but the allegation was examined by professional standards.

‘He was not required to resign from the force. He left voluntarily. He is not aware of any anti-corruption investigation ever taking place.’

Northamptonshire police spokesman said: ‘We have a brief digital record confirming a misconduct process in 2002.’ The force said it could not find any further information as its records at the time ‘would have been paper-based’.