Chinese authorities have been tracking millions of people in its far west region of Xinjiang using a DNA database with the help of American expertise, it is claimed.

According to The New York Times, Chinese officials presented the blood tests as part of a free health check-up programme in its surveillance campaign primarily on the country's Muslim Uighur minority.

Human rights groups and Uighur activists say officials can use such genetic material to chase down any Uighurs who resist conforming to the campaign, the report said.

China's Uighur ethnic minority lives has been subjected to heavy police surveillance in recent years. The New York Times reported that officials have been using DNA samples to track them

Scientists affiliated with China's police used equipment produced by Thermo Fisher, a US biotechnology manufacturer, according to the New York Times.

Since 2016, there have been regular reports of Chinese authorities taking blood samples in the Xinjiang region. Some 36 million people have participated, according to Chinese state news agency Xinhua - more than just the Uighur population.

Xinjiang is home to most of China's Uighur ethnic minority and has been under heavy police surveillance in recent years after violent inter-ethnic tensions.

Policemen patrol past a building's wall mounted with surveillance cameras in Peyzawat in Xinjiang. Officials have been using DNA samples to track millions of people, it is claimed

Scientists affiliated with China's police used equipment produced by Thermo Fisher, a US biotechnology manufacturer, according to the New York Times

Nearly one million Uighurs and other Turkic language-speaking minorities in China have reportedly been held in re-education camps, according to a UN panel of experts.

Tahir Imin, a 38-year-old Uighur, told The New York Times that he had his blood drawn, his face scanned and his voice recorded by the authorities in Xinjiang during a check-up.

But when he asked to see the results, they denied his request and told him he did not have the right to ask for it.

In spring 2017, Human Rights Watch claimed China had ordered equipment to increase DNA sequencing capabilities - which American scientific journal Nature then confirmed, naming Thermo Fisher as a supplier.

A perimeter fence is constructed around what is officially known as a vocational skills education centre in Dabancheng in China's far-west Xinjiang region

Following the report, Thermo Fisher issued a statement on Thursday saying it would no longer sell its equipment in Xinjiang.

'As the world leader in serving science, we recognize the importance of considering how our products and services are used - or may be used - by our customers,' a company spokesperson said to AFP.

Despite its low public profile, Thermo Fisher is a scientific equipment giant, with US$24.3 billion (£18.7 billion)in revenue last year.

In a statement cited by the New York Times, the Xinjiang government denied that it collects DNA samples as part of the free medical checkups. It said the DNA machines that were bought by authorities were for 'internal use'.