The accusation has been made by La Cimade, a French NGO which assists foreigners in protecting their rights, which says it has had "numerous testimonies" from migrants who were illegally charged by doctors for providing them with medical certificates.
An investigation is underway into one doctor, who was suspended from the Pitié-Salpêtrière Hospital in Paris's 13th arrondissement last Tuesday for repeatedly charging migrants for medical certificates .
And La Cimade argues that this is not an isolated case.
"This case is the tip of the iceberg," said Laura Petersell, who works in the health department of La Cimade, speaking to Le Parisien. "We have confirmed that numerous doctors have extorted migrants. They demand payment of several hundreds of euros in exchange for the medical certificates confirming an illness which might entitle them to a residence permit."
Consultation is usually covered by health insurance for migrants who receive AME (medical aid from the state) or CMU (universal health coverage).
Petersell said that La Cimade had "numerous testimonies" from migrants who had been charged for their medical certificates, and that the organization had reported the cases to France's Ministry of Health.
The president of the Ethics committee of France's Medical Assocation, Dr Jean-Marie Faroudja, confirmed: "There are no excess fees to be charged to vulnerable patients under the CMU," and that "such failures justify disciplinary proceedings."
Faroudja added: "These are unacceptable practices."