David Sullivan has faced restrictions on his contact with West Ham’s women’s and youth teams since 2023 because of a safeguarding investigation.

The Football Association began an inquiry three years ago after receiving a complaint, which the Guardian understands involves an allegation of sexual misconduct unrelated to football.

Sullivan, the club’s largest shareholder, said through lawyers on Wednesday morning that the restrictions were part of a “negotiated and temporary agreement”. The 77-year-old billionaire added that the safeguarding investigation related to a “single anonymous complaint” from an “event in 1981” that he says “never happened”.

Sullivan announced his resignation as a director and co-chair of West Ham on Saturday, before the publication of a joint investigation by the BBC and the Times in which seven women accused him of abusing his power and preying on them for sex, in claims that date back to the 1980s and 1990s.

He retains his financial stake in the east London club, though he could be forced to sell his shares by the football regulator, which described the allegations as “extremely serious”.

Three women claimed that the former pornography baron had abused his power as the owner of the Daily and Sunday Sport newspapers to prey on them for sex when they were seeking work. A further four accused him of exploitative and predatory behaviour, including allegations he had tried to pressure them into sex during business meetings.

Through his lawyers, Sullivan has “categorically” denied the allegations, which the BBC and Times said involved women then in their late teens and early 20s.

Sullivan said: “After a lifetime spent building businesses in the adult industry, in which I have met thousands of women, it is sadly inevitable that a small number of improper conduct claims are being made against me.”

In a new statement issued on Wednesday morning, Sullivan said: “I wish to clarify recent media reports regarding a negotiated agreement with the Football Association (FA), which has been inaccurately described as a disciplinary ‘ban’.

“In my entire 16 years at [West Ham] I have never met any academy or women’s team players [one to one], therefore a negotiated and temporary agreement with the FA not to do so until the FA resolved an outstanding complaint in relation to a single anonymous complaint regarding an event in 1981 was entered into.

“The complaint had nothing to do [with] my time in football and it never happened. I saw it as a meaningless restriction, as it didn’t impact on my work in any way, therefore I accepted it for a quiet life.”

On Tuesday evening, Lisa Nandy, the culture, media and sport secretary, described the latest revelations as “utterly horrifying”.

She said: “If it is the case that an investigation concluded that there were sufficiently serious allegations to warrant a ban on contact with the youth and women’s teams, then the FA must explain this decision and why no further action was taken. I expect a full and urgent explanation from the FA and West Ham as to how these incredibly serious allegations have been handled.”

A spokesperson for West Ham said the club could not comment on individual cases but that it had “clear and robust safeguarding measures in place, measures that are independently assessed and audited on an annual basis”.

The FA has not clarified whether the safeguarding investigation has been resolved. A spokesperson said: “We take all safeguarding allegations and concerns very seriously, and we investigate each case within our jurisdiction thoroughly.

“Appropriate action is always taken against individuals who pose or may pose a risk of harm to children and adults at risk in football. This includes issuing appropriate suspensions in accordance with our safeguarding regulations.

“The aim of our process is to safeguard children and adults at risk, and we are unable to comment on individual safeguarding matters, including cases that remain active.”