LONDON — The police in Britain are investigating a new allegation of sexual assault against Harvey Weinstein, the 11th case in the country against the American movie producer, who was disgraced when dozens of women came forward last year to accuse him of sexual misconduct.

The Metropolitan Police said in an email on Tuesday that it received an allegation of sexual assault by a man against a woman in the early 1990s, in a case connected to what the police call “Operation Kaguyak.”

The statement did not identify the accused person as Mr. Weinstein, following the usual procedure of withholding personal details until a person is charged. But news reports have widely linked the operation to the allegations in Britain against Mr. Weinstein. A representative for Mr. Weinstein declined to comment on the matter.

Mr. Weinstein, who has denied accusations of nonconsensual sex even as more than 80 women have said that he sexually harassed or assaulted them, was arrested in New York in May and has been charged with sexually assaulting at least three women.