Italian police said on Wednesday they had smashed a “macrobiotic sect” run by a 73-year-old guru and businessman who allegedly reduced followers to slavery by rigidly controlling their diets and denying them contact with the outside world.

Fourteen people were arrested in the Marche region of central Italy and five placed formally under investigation on suspicion of running a criminal gang tied to slavery, mistreatment and tax evasion, judicial sources said.

Investigators began an inquiry in 2013 when a young girl in the town of Forli denounced to police promises by the guru that his diet could miraculously heal otherwise incurable illnesses, police said.

Those under investigation included guru Mario Pianesi, 73, his wife Loredana Volpi, 51, and two other collaborators, police said. Followers allegedly were manipulated to follow a rigidly controlled five-stage diet called “Ma.Pi.,” coined after the name of their leader.

The weight of one female follower was reduced to as little as 35kg (77lb), though she had no weight problems beforehand, police sources said.