British researchers say the world’s production of solar panels is being fuelled by forced labour from Uighur Muslims in the Chinese province of Xinjiang.

An investigation by Sheffield Hallam University says some 45% of the world’s supply of a key component in the panels – polysilicon – comes from Xinjiang and is obtained through a vast system of coercion involving the Uighur ethnic minority.

In Broad Daylight, the report from the university’s Helena Kennedy Centre for International Justice, says the world’s four biggest panel manufacturers use polysilicon tainted by forced labour, and urges producers to source the substance from elsewhere.

It cited an official Chinese government report published in November which documented the “placement” of 2.6 million “minoritised” citizens in jobs in farms and factories in Xinjiang and elsewhere in the country through state-sponsored “surplus labour” and “labour transfer” initiatives.

Many indigenous workers are unable to refuse or walk away from these jobs, and thus the programmes are tantamount to forcible transfer of populations and enslavement

“The (Chinese) government claims that these programmes are in accordance with PRC (People’s Republic of China) law and that workers are engaged voluntarily, in a concerted government-supported effort to alleviate poverty,” the report says.

“However, significant evidence – largely drawn from government and corporate sources – reveals that labour transfers are deployed in the Uighur Region within an environment of unprecedented coercion, undergirded by the constant threat of re-education and internment.

“Many indigenous workers are unable to refuse or walk away from these jobs, and thus the programmes are tantamount to forcible transfer of populations and enslavement.”

The report said the issue was exacerbated by the fact 95% of all solar modules relied on solar-grade polysilicon, which is extracted from mined quartz.

It said all polysilicon manufacturers in the Uighur region had “reported their participation in labour transfer programmes and/or are supplied by raw materials companies that have”.

The report’s authors said they had “investigated the entire solar module supply chain from quartz to panel” to better understand the extent to which forced labour in Xinjiang affected international solar panel supply chains, in order to “provide stakeholders with the evidence base upon which to judge risk of exposure to forced labour”.

China has drawn increasing international condemnation over its treatment of Uighur Muslims, including allegations of mass detentions and human rights abuses including forced labour and the forcible sterilisation of women.

In March, the UK, US, Canada and the European Union placed sanctions on Chinese officials deemed to be responsible for human rights abuses in Xinjiang.

Foreign Secretary Dominic Raab said the abuse of the Uighur Muslims in Xinjiang was “one of the worst human rights crises of our time” and the international community “cannot simply look the other way”.