Paris Cité University has revoked the doctoral degree of physicist Étienne Klein following a 20-month administrative investigation. The investigation determined that approximately two-thirds of Klein’s doctoral thesis were plagiarized. Initial accusations of plagiarism in Klein’s published works surfaced in 2016, prompting scrutiny of his academic credentials. The university’s decision marks the conclusion of a ten-year-long controversy surrounding the originality of his research. This action follows a thorough review process and confirms the validity of the plagiarism claims. Klein, formerly a research director at the French Alternative Energies and Atomic Energy Commission (CEA), has faced public criticism regarding his scientific integrity. The university has not released further details regarding the specific instances of plagiarism.