British Security Minister Tom Tugendhat said on Tuesday China had closed reported “police service stations” at sites across the United Kingdom and that an investigation had not revealed any illegal activity by the Chinese state at these sites.

Britain has previously said reports of undeclared police stations in the country were “extremely concerning” and that any intimidation on British soil of foreign nationals by China or other states was unacceptable.

China has denied operating any such stations and issued a statement contesting Tugendhat’s remarks via its embassy in London, saying the accusations of running police posts in the U.K. were a “complete political lie.”

British police have investigated claims made by the nongovernmental human rights organization Safeguard Defenders that such police stations were operating at three British sites, Tugendhat said in a written statement to parliament.

“I can confirm that they have not, to date, identified any evidence of illegal activity on behalf of the Chinese state across these sites,” he said.

“We assess that police and public scrutiny have had a suppressive impact on any administrative functions these sites may have had.”

The Chinese government has previously said there are centers outside China run by local volunteers, not Chinese police officers, that aim to help Chinese citizens renew documents and offer other services.

U.S. federal agents arrested two New York residents in April for allegedly operating a Chinese “secret police station” in the Chinatown district of Manhattan. China had said it firmly opposed what it called “the U.S.’s slanders and smears.”

The British government has said it was aware of about 100 such stations around the world.

“The Foreign Commonwealth and Development Office have told the Chinese Embassy that any functions related to such ‘police service stations’ in the U.K. are unacceptable and that they must not operate in any form,” Tugendhat said.

“The Chinese Embassy have subsequently responded that all such stations have closed permanently. Any further allegations will be swiftly investigated in line with U.K. law.”

Asked about Tugendhat’s statement, a spokesperson for the Chinese Embassy in London said in a statement translated from Mandarin by Reuters:

“There is simply no existence of so-called ‘overseas police posts.’ The facts have proven that the so-called ‘overseas police posts’ [are] a complete political lie, and politicians who speculate on this topic are purely in political manipulations.

“The Chinese government urges the U.K. government to stop spreading false information, to stop generating hype and slandering China.”