Chennai: DMK President M.K. Stalin on Thursday demanded a probe by Central Bureau of Investigation (CBI) into the hiring of proxies to write the medical entrance exam - National Eligibility cum Entrance Test (NEET). Speaking to reporters in Tiruvarur, Stalin said brokers from Tamil Nadu as well as other states are involved in this crime. He said if justice is to be obtained, the probe should be done by the CBI. Currently, the case is being investigated by the Crime Branch Crime Investigation Department of Tamil Nadu police. To date, police have arrested four father-son duos for allegedly hiring proxies to write the entrance exam. (IANS)