"One possibility is that Gurshan Singh Channa died of natural causes and someone panicked and disposed of his body," The Herald Sun reported.
According to the report, police hope toxicology tests and some others can provide some answers.
Meanwhile, Gurshan Singh's parents paid their respects to their son at the city's morgue on Saturday, Mar 6.
Gurshan's body was found on Thursday night, Mar 4 at Oaklands Junction, 30 km from the Lalor home.
An autopsy has failed to identify a cause of death, and his body showed no signs of violence.