The boy had won several medals in swimming and was practising for a competition.
Police said his mother had died six months ago and his father Sridhar had taken voluntary retirement from a private job to take care of the boy.
Police sources said that there is no suspicion about his death, but viscera samples have been sent for forensic analysis.
Sources said he was later declared brought dead.The Guindy police registered a case of natural death and moved his body to the Royappetah General hospital for a postmortem.
The body was later handed over to his father.