The three, arrested last night, were running clinics in Jederpalayam, Paramathy and Valavanthinadu.
47-year old Parthasarathi had studied ayurveda but was prescribing allopathy medicines to patients in Paramathy while Ramesh (32) of Jederpalayam had a non-medical degree and the other person was a class X pass and practising medicine in the hilly Valavanthinadu, police added.