There were several injury marks on the body which was found naked, police said, adding they suspected that the youth, in his early 20s, was beaten up before being murdered.
A passerby informed the police about the body floating in the canal, they said.
The body was fished out and sent for a postmortem.
Preliminary investigations suggested that the youth had been dumped in the canal two to three days ago, police said.
Further probes are on, they added.