Mahesh Tanna received the letter on Tuesday. Pic/Suresh Karkera

Hours after cops filed a 1,000-page chargesheet in the Hiranandani kidney racket, Mahesh Tanna, a social worker who is also the complainant in the case, received a letter from a 'Group of doctors', which was laced with threats. Tanna has been warned through the letter to stay away from the case or face consequences.