According to a newspaper report, immigration officials are probing allegations that Dhillon was in the country on a fake passport.
"Allegations have been made that the man charged is being investigated for possible immigration fraud," said a spokesperson at the Department of Immigration.
Dhillon, who worked as a part-time driver, has been accused of dumping the body of three-year Gurshan Singh Channa nearly 20 kms from his home after he was reported missing by his parents on Thursday, Mar 4.
He allegedly put the unconcious Gurshan at the boot of his car before dumping the body.
Dhillon's agrieved wife, Sim Kaur, was quoted in the newspaper report as saying that 'everything has gone wrong'.
The accused shared the house with Gurshan's parents. The victim had come on a holiday with his parents in Jan 2010 and was about to return to India when the incident took place.