Missing Sydney man Raveshan Pillay reportedly slipped through the hands of survivors when the whale watching boat he was on capsized.
Royal Canadian Mounted Police Constable Jim Preston has told The Times that one of the survivors may have been a family member of Mr Pillay's girlfriend, Danielle Hooker, who lost her father in the incident. It is understood Mr Pillay was unconscious at the time.
"A group of survivors fought to keep him afloat. At least one of them was a female family member," Mr Preston said.
"They were holding on to him [until the] point they couldn't hold on to him any longer and he went under."
Mr Pillay, who has been described as a loving and caring brother and son, remains missing after a Canadian whale watching boat he was on sunk.
The 27-year-old was on the boat with 28-year-old Ms Hooker, and her family when it capsized off Vancouver Island on Monday, leaving five Britons dead.
Mr Pillay's parents and brother were on the way to Canada on Wednesday.
"The Pillay family would like to thank family and friends for their support during this difficult time," a spokesman told AAP earlier this week.
"Raveshan was a loving and caring son and brother."
Canadian authorities have described how a tranquil cruise quickly turned to chaos.
A preliminary investigation into Sunday's sinking of the 20m, double storey MV Leviathan II points to a wave hitting the vessel.
Most of the 27 tourists and crew on the doomed boat were believed to be on the left side of the top, open deck when the wave struck the right side, rolling the boat.
The sightseeing trip instantly turned into a fight for survival, with the passengers and crew tossed around like rag dolls, trapped inside or attempting to stay alive in frigid waters.
"It was a very chaotic situation," Matt Brown, the regional coroner for the Island Region of the British Columbia Coroners Service, told reporters on Tuesday.
Mr Pillay remains missing despite a wide-scale search by authorities, including divers and members of the public.
The search has spread to nearby islands in the hope the Australian was able to swim to land.
Along with the father of Mr Pillay's girlfriend, the two other Brits who died were David Thomas, 50, and son Stephen, 18, who had Down Syndrome.
In the moments before the tragedy something, possibly a seal on a nearby reef, captured the sightseers' attention, resulting in most of the people on the top deck moving to the left side of the vessel.
"This would have raised the centre of gravity, affecting its stability," Marc Andre Poisson, director of marine investigations at the Transportation Safety Board of Canada, said.
The vessel tilted up, rolled and then capsized.
There were more than enough life vests for everyone but because of the size of the vessel and the waters it was in, passengers did not have to wear them.
News break – October 30