Bloom reportedly warned Xu in the letter that he would “not receive the continued support of the School for you or your research if you persist in exercising independent action” and that his continued efforts to silence critics would lead to “appropriate sanctions.”

In his research, which was chiefly sponsored by Harvard and Cambridge-based Millennium Pharmaceuticals, Xu took blood samples from thousands of poor peasants and farmers in Anhui province of rural central China.

The Post article alleges that Xu did not inform the donors of his purpose in taking the blood—a violation of the regulations of the National Institutes of Health (NIH)—and that he did not provide medical treatment that he had promised in exchange for the donations.

Part of the project was funded from federal research monies, meaning that the research was required to follow federal regulations.

The Post reported that the blood was taken in order to create a genetic databank for further scientific use.

Genetic material is particularly valuable from residents of Anhui because of its very isolated nature, which creates a unusually homogenous gene pool.

William Hall, a spokesperson for the human research office in the federal department of Health and Human Services, confirmed a federal investigation of Xu’s research is underway. However, he would not provide any further details.