Marineland, a now-shuttered tourist attraction near Canada's iconic Niagara Falls, has faced intense scrutiny for years.

The Canadian Press news agency has reported that 20 whales -- one killer whale and 19 belugas -- have died at the park since 2019.

Animal welfare inspectors in the province of Ontario have been investigating Marineland since 2020 and have previously declared that all animals at the park were in distress due to poor water quality.

Once a popular destination for tourists visiting the Niagara Falls region, Marineland closed to the public last year and has reportedly been trying to sell off assets.

Canada's fisheries minister, Joanne Thompson, said Wednesday that she had denied Marineland's request to export 30 belugas to the Chimelong Ocean Kingdom theme park in China.

China's multi-billion dollar Chimelong park, in Zhuhai, claimed to be the world's largest ocean theme park when it opened a decade ago.

"I could not in good conscience approve an export that would perpetuate the treatment these belugas have endured," Thompson said in a statement.

The 30 belugas at Marineland are the last captive whales in Canada.

"Whales belong in the ocean, not in tanks for our amusement," added Thompson, who blocked the export request under authority granted through 2019 legal revisions aimed protecting marine mammals.

Marineland sent five belugas to the Mystic Aquarium in the US state of Connecticut in 2021. By the end of 2023, three of those whales had died.