COPENHAGEN, Denmark, Sept. 21 (UPI) -- A Swedish doctor who was fired for using a controversial technique to cure pain has turned up on staff in the psychiatric ward of a Copenhagen hospital.

Danish authorities said they weren't aware of the background of the man the media dubbed "Doctor Anal" for developing "anal massage" as a cure for various kinds of pain, The Local reported Friday.

"It is tricky to carry out background checks on foreign doctors because rules vary from country to country," Danish welfare board spokeswoman Anne Mette Dons told the newspaper Ekstrabladet.

The unnamed doctor was fired from his job in Sweden after being cited by the country's Medical Responsibility Board for using anal massage to treat an elderly woman for headaches and back pain.

He was dismissed from a job in Norway after hospital authorities learned of his background.

"I have a personality disorder, or rather a syndrome, a former of Aspergers," the doctor told a reporter. "I am different but cleverer."