Chinese birth control policies could cut between 2.6 to 4.5 million births of the Uyghur and other ethnic minorities in southern Xinjiang within 20 years, up to a third of the region’s projected minority population, according to a new analysis by a German researcher.

The report, shared exclusively with Reuters ahead of publication, also includes a previously unreported cache of research produced by Chinese academics and officials on Beijing’s intent behind the birth control policies in Xinjiang, where official data shows birth-rates have already dropped by 48.7% between 2017 and 2019.