New Delhi: The father of a Dalit JNU student, who was found dead two days ago at a friend's house in south Delhi, has ruled out suicide, alleging that his son was battling "caste-based harassment discrimination in his academic pursuits" at the university.The father's claim came hours after Delhi Police said it was investigating it as suicide and registered abetment of suicide charges against unknown persons."The police have also registered a case under Scheduled Castes and Scheduled Tribes (Prevention of Atrocities) Act," Additional Deputy Commissioner of Police Chinmoy Biswal said.J. Mathukrishnan, 29, an MPhil student at Jawaharlal Nehru University (JNU), was found hanging from a ceiling fan at his friend's place in Munirka Vihar on Monday.His 53-year-old father, Jeevandhaam, has told police that his son could not have committed suicide because his body carried no such indications."I was shown the photographs of the body hanging from the ceiling fan with a cloth, his knees bent and his feet touching the ground. The position of the body as seen from the picture raises serious doubts about the alleged claim of my son committing suicide," Jeevandhaam said in his written statement to police. A copy of the statement is with IANS."In the picture the tongue was not protruding and his eyelids were not drooping, which is normally seen in such cases," the father said.He said his son son was not diagnosed with any mental illness and was not under any medication for depression or other mental illness."The death of my son has taken place under circumstances and I request police to conduct thorough investigation in the suspicious death, not suicide, of my son and to register an FIR under the appropriate sections."All India Institute of Medical Sciences (AIIMS), however, ruled out any foul play in the death after a five-member medical board conducted an autopsy. The board said the death was due to asphyxia and that no injury mark was found on the body.Jeevandhaam said his son had long cherished the dream to study at JNU and took up odd jobs to finance his education in Hyderabad Central University and for his further studies.He said Mathukrishnan got JNU admission after several attempts and wanted to pursue a career in civil services.