LONDON — Hundreds of officers and other employees of the police in Britain have allegedly used their power to sexually abuse vulnerable people, a report released Thursday by a national watchdog agency said, the latest in a string of institutional abuse accusations in the country.

Among those targeted, in what the agency called “the most serious corruption issue facing the service,’’ were victims of domestic abuse, those struggling with substance abuse, and people who work in the sex industry, some of whom were in custody at the time.

The agency, Her Majesty’s Inspectorate of Constabulary, which assesses national police forces, found that there had been 436 accusations of sexual abuse by police officers in England and Wales over the two years through the end of March. It said the accusations involved 334 police employees, including 306 officers. The agency also said the scale of the problem was much larger.

The leader of the inquiry, Mike Cunningham, a former chief constable of the Staffordshire police, said the abuse was an egregious breach of officers’ roles as protectors.

“What can be worse than a guardian abusing the trust and confidence of an abused person? There can be no greater violation of public trust,’’ he said in the report. “It is an exploitation of power where the guardian becomes the abuser.’’

The latest report comes as Britain has been grappling with a series of scandals that have called into question how institutions respond to those who are vulnerable to abuse.

New York Times