Volunteer group Doctors of the World threatened legal action on Thursday after its medical center in downtown Athens was raided by police following alleged complaints that medics were not following the law when issuing medication for mental illnesses.

The police did not find anything untoward at the medical center. The aid organization said it was the second such check in the last two weeks and that it would consider suing authorities to find out who had been making defamatory claims about Doctors of the World, also known as Medicins du Monde.

The group said that it would continue to treat patients for free, regardless of whether they are Greeks or immigrants.