Police don't know who dumped body in Victorian toilet block

Police know when the body of a suspected illegal migrant was dumped in a Victorian toilet block, but they don't yet know who put it there.

Mystery continues to surround the discovery of the man's body in a public toilet block at Boundary Bend, a small rural town near the Murray River.

Police believe the Asian man, 47, is an illegal migrant who likely died on a farm before his body was dumped at the highway rest-stop on Friday.

His illegal status could explain why the man did not go to hospital, despite being seriously ill, and why someone then opted to dump his body.

Investigators know the man's name and have narrowed down the time when his body could have been dumped in the toilet block, which is beside a busy highway, to 8.30am - 9am on Friday.

Any Victorian farmers who hired an Asian man who appeared ill have been asked to contact police, who are preparing a report for the coroner.

Border Force is also investigating.