More than 100 Chinese research papers have been removed this year by well-known global publications.

These removals were based on findings that some authors had forged third-party peer reviews or simply had others write for them.

Investigations showed many third-party institutions were in reality companies providing ghost writing services for a fee. They forged emails of experts and sent in positive reviews to the publishers.

China's National Natural Science Foundation has revoked funding for authors caught in the scandal. More severe punishments include removal of their professorships.

The foundation says plagiarism and dishonesty in academia should be treated with zero-tolerance, while noting most Chinese researchers are honest.