Thongchai Saengprathum, secretary of the Khao Yai Foundation, said the |officials concerned should face legal action for |negligence during the February 11 incident.

The bear woke up aboard the helicopter while it was being flown into the national park in Prachin Buri. It had not been put inside a cage but was instead covered by a net and put on board. As the helicopter flew over forest land, the animal panicked and fell to its death.

The young bear, which weighed about 90 kilograms, had been found injured in November last year and officials took it for rehabilitation until it fully recovered.

Thongchai said the accident could have been avoided, as Khao Yai National Park had been a role model for other parks in its handling of rescued wild animals.

He said the park |officials made a wrong decision to fly the bear in a helicopter because other wild animals were earlier transported in trucks to be released back to nature.

Thongchai also said the plan to release the bear at Khao Laem, which is deep in the forest and far from the spot near the forest border where it was found and rescued, was flawed.

He said Asian black bears are social animals that need to stay with their packs. Flying the bear to a new location could also see it killed by local bears, Thongchai added.

The activist said officials were also careless in calculating the weight of the bear to give the correct dose of tranquilliser to prevent it from waking up during the operation. It should also have been put it a cage, he said.