LONDON (AP) — An independent monitor of Britain's use of surveillance cameras has asked for the government to clarify its positions on buying equipment from a Chinese technology company accused of involvement in human rights abuses.

Fraser Sampson, the biometrics and surveillance camera commissioner, said he raised concerns with senior Cabinet officials after Hikvision failed to answer questions about the extent of its role in China's treatment of Uyghurs and other Muslim minorities in western Xinjiang province.

“There are serious unanswered questions about Hikvision’s involvement in appalling human rights abuses in China," Sampson said in a statement Tuesday. “The company seems unwilling or unable to provide assurances about the ethics of some of its operations and about security concerns associated with its equipment.”

Sampson said the company's cameras and facial recognition technology have been implicated in “systematic human rights abuses” against Uyghurs. He said widespread persecution of the minority group in Xinjiang “is known to rely heavily on surveillance technology, including facial recognition software designed to detect racial characteristics.”

British media have reported that the U.K. health department banned Hikvision from competing for new business after a procurement report found “ethical concerns” about the company.

Sampson said all branches of the British government should rule out contracts with Hikvision until the company provides necessary information on ethics and security.

Hikvision, which is headquartered in Hangzhou, China, did not immediately respond to requests for comment Tuesday. The company's website says its products are used in more than 150 countries and regions and that it employs more than 42,000 people worldwide.