"A man indeed died. We don't know what kind of sickness he died from, but they had to have the funeral in the high seas," David Poopala Pillai, a spokesman for the Canadian Tamil Congress, told AFP.
The man was in his mid-thirties, said Poopala Pillai, who was unable to provide further details about the death.
"Details are very sketchy," the spokesman in Vancouver said, adding that a team of 10 lawyers working with the Canadian Tamil Congress was informed of the incident after meeting with migrants at correctional facilities near Vancouver on Sunday.
The migrants await the start on Monday of legal detention hearings.
On Saturday, Canadian authorities said that the estimated 490 migrants were in good condition, despite a three-month journey aboard the MV Sun Sea, a rusty 59-meter (194-foot) Thai-registered ship.
"The people (aboard) were in fairly good health and they were fairly cooperative," said Rob Johnston, regional executive director for the Canada Border Services Ag