The authorities have said the 50-year-old psychotherapist is being held without bail. He is charged with two counts of manslaughter and six counts of aggrevated assault.

Prosecutors said on Sunday that the doctor had admitted to giving "various substances and psycho drugs" to 12 patients during group therapy in his Berlin practice.

One patient managed to send a text message to emergency services as all 12 collapsed with poisoning symptoms during Saturday's group session.

A 59-year-old man died soon after the drugs were administered, and a 28-year-old man in a coma died later in hospital.

Police said a third man was in critical condition, but that the other nine had been discharged from hospital.

No evidence of intent to injure

It is unclear why the doctor administered the risky mix of psychopharmaceuticals, but media reports suggest he wanted to tap his patients' subconscious during the therapy session.

Eva Jaeggi, a renowned psychotherapist also practicing in Berlin, said the use of uncontrolled drugs had nothing to do with proper psychotherapy.

Jaeggi told German public radio that "it is a clear example of charlatanism for a physician to prescribe untested drugs to his patients. He calls himself a psychotherapist. But this just isn't psychotherapy."

Investigators, meanwhile, have said they have yet to discover evidence indicating the doctor had deliberately wanted to injure any of his patients.

glb/nk/dpa/AP

Editor: Jennifer Abramsohn