Tilikum, an orca who killed a trainer at an aquarium near Victoria before being linked to the deaths of two more people at a Florida facility, has died in captivity at SeaWorld Orlando.

The whale estimated to be 36 was profiled in the 2013 documentary "Blackfish" and helped sway the public against keeping killer whales in captivity.

SeaWorld officials did not give a cause of death but said in a statement Friday that Tilikum had faced serious health issues including a persistent and complicated bacterial lung infection.

The statement said a necropsy will be performed on the orca, noted for his size at 6.7 metres and nearly 5,500 kilograms.

SeaWorld president Joel Manby said Tilikum was cared for by a team of people at the facility in Orlando.

"Tilikum had, and will continue to have, a special place in the hearts of the SeaWorld family, as well as the millions of people all over the world that he inspired," he said in a statement.

SeaWorld said the orca "was near the high end of the average life expectancy for male killer whales, according to independent scientific review."

However, Peter Hamilton of Vancouver-based Lifeforce, which has fought against whales in captivity for decades, said male orcas live up to 60 years in the wild.

He said Tilikum suffered deep psychological stress after being captured in Iceland in 1983 at about age two, when he was brought to Sealand of the Pacific in Oak Bay, B.C.

Hamilton credited Tilikum for raising awareness of the dangers of keeping whales in captivity after the orca attacked and killed trainer Dawn Brancheau at SeaWorld Orlando in 2010 during a live show before a horrified audience.

The whale was also involved in the 1999 death of a man who snuck into the SeaWorld facility past security and jumped or was pulled into the pool.

Hamilton said Tilikum was confined to a small holding tank for months at Sealand after he was captured and placed in the enclosure every night after the facility was closed.

On Feb. 21, 1991, Tilikum and two female orcas at Sealand were linked to the death of trainer Keltie Byrne, who slipped and fell into a pool.

Tilikum was moved to SeaWorld Orlando in January 1992 by its owner, Bob Wright, who is said to have sold the orca for US $1.2 million. He closed Sealand about a year later following heavy criticism by environmentalists.

Hamilton said Lifeforce's founding director predicted "Tilly" would kill other people following Byrne's death and that the group made recommendations in response to an inquest into the trainer's death, and also advised SeaWorld against putting people in the pool with the whale.

"Tilikum certainly brought hope to end cetacean captivity," Hamilton said. "He brought tension to the fact that these animals suffered physically and psychologically when imprisoned in aquarium tanks. It's not humane to keep them in captivity and it's not safe for people who have to work with them."

He said a joint project by Lifeforce and Greenpeace stopped Wright and his crew from capturing the endangered southern resident whales near Victoria at Pedder Bay.

"After 30 days they gave up because Greenpeace had the Zodiacs there, we had ultralights there to make sure that if the orcas came by the Zodiacs would go out and keep them away from the capture nets.

"But a few months later he brought whales in from Iceland."

Tilikum was among three whales Wright purchased in Iceland in 1983 and 1984, when orcas were fetching about $200,000 each and could be bought by anyone with a federal permit. 

Last March, six years after Brancheau's death and three years after the release of "Blackfish," SeaWorld announced it would end its breeding program.

Camille Bains, The Canadian Press