The papers by different scientists are all based on research that draws on DNA samples collected from populations in China. In several cases, the researchers used samples from populations deemed by experts and human rights campaigners to be vulnerable to exploitation and oppression in China, leading to concerns that they would not be able to freely consent to such samples being taken.

One retracted paper studies the DNA of Tibetans in Lhasa, the capital of Tibet, using blood samples collected from 120 individuals. The article stated that “all individuals provided written informed consent” and that work was approved by the Fudan University ethics committee.

But the retraction notice published on Monday stated that an ethical review “uncovered inconsistencies between the consent documentation and the research reported; the documentation was not sufficiently detailed to resolve the concerns raised”.