JOHANNESBURG - A South African witch doctor's medicine recipes landed him in trouble with the law when police found him using human bones he had dug up from graves to treat mental illness.

Muti, or traditional medicine, uses herbs, barks and animal parts as legal treatments for minor ailments like headaches and bad dreams, and as potions said to boost sexual performance.

But human body parts are banned from the mixture, police spokesman Mohale Ramatseba said, adding that the 39-year-old man had been arrested Friday in the northern Limpopo province for violating graves and possessing human bones.

"He had dug them from graves. He said he was healing people who were mentally ill, so he dug up the bones of people who had died," Ramatseba told Reuters, adding that police were rounding up similar offenders in the area.