The Ontario government says Kiska, the last captive killer whale in Canada, has died.

A spokesperson for the solicitor general says Marineland — the Niagara Falls, Ont., theme park where Kiska lived — told the province she died on Thursday.

Brent Ross says the province's Animal Welfare Services officers were on-site as Marineland performed a necropsy.

Kiska is believed to have been 47 years old and was captured in Icelandic waters in 1979.

She was captured alongside Keiko, who became famous in the movie Free Willy, and the pair lived together for a few years at Marineland in the 1980s.

Marineland's owner declined to comment when reached by phone.

Animal Justice, a Canadian non-profit group which aims to protect animal rights through the legal system, mourned Kiska's death and renewed calls for investigations into Marineland's treatment of the orca.

"It is heartbreaking to know that Kiska will never have the chance to be relocated to a whale sanctuary, and experience the freedom that she so deeply deserved," Camille Labchuk, executive director of Animal Justice, said in a statement.

"We are demanding justice for what Kiska endured at the hands of Marineland," Labchuk added.

"We are calling on provincial authorities to make public the results of a post-mortem, and prosecute Marineland for the unlawful distress Kiska clearly experienced throughout her final years."

Animal Justice lodged a legal complaint in July 2021 against Marineland's treatment of Kiska, accusing it of breaking the law by not meeting her physical and mental needs. The complaint followed videos posted by Phil Demers — a former trainer at Marineland — which appeared to show Kiska floating listlessly and moving slowly.

Later that same year, Marineland was charged criminally after Animal Justice filed another complaint alleging dolphins were being forced to perform for entertainment despite a national ban. The charges were stayed in December 2022.