Cambridgeshire's chief constable, Tom Lloyd, has resigned after newspaper claims that he made inappropriate sexual comments to a woman official.
Tom Lloyd apologised for any offence he caused
A statement issued on Wednesday said Mr Lloyd, 53, was resigning to safeguard the reputation of the Cambridgeshire Constabulary.
According to the Daily Mail, the woman was allegedly "pestered" during a police conference in Birmingham.
The woman reportedly made no official complaint about the alleged incident.
In his resignation statement Mr Lloyd said: "This decision follows reports of my behaviour at a social event at the recent Conference of the Association of Chief Police Officers.
"However ill-founded or exaggerated the reporting, I recognise that I gave cause for concern to those present.
"The subsequent media attention has damaged my reputation, and I feel honour-bound to step down before endangering the reputation of the constabulary that I have been proud to lead for the last three years.
"As chief constable my integrity, professionalism and commitment must be beyond reproach in order to command the respect of the force, the members of the Police Authority to whom I answer, and, most importantly, the community that I serve.
"I deeply regret that a moment of foolishness may have caused some to question my integrity."
Cambridgeshire Police Authority chairman Michael Williamson said Mr Lloyd had led the force through some difficult times and he was accepting his resignation with regret.
"The authority would like to make it clear that, despite recent media speculation, no formal complaint has been made against Mr Lloyd and the decision is a personal one which we respect and support," he said.
Mr Lloyd was appointed chief constable shortly before schoolgirls Holly Wells and Jessica Chapman went missing from Soham in August 2002.
He faced criticism when it emerged that he had gone on a family holiday during the hunt for the missing schoolgirls, while many of his officers were putting in 20-hour days.
He cut the trip short and returned home.
Mr Lloyd was later called as a witness in the Bichard Inquiry into how police cleared the girls' killer, Ian Huntley, to work at a college despite a string of sex allegations.
Mr Lloyd told the inquiry that he took full responsibility for errors made and failings in vetting processes.
Deputy Chief Constable Julie Spence will be taking over the post temporarily.