Locals informed the Department of Forest and the Department of Environment on seeing the whale at Himchhari on Friday afternoon.
“The whale has rotten red and smelt foul,” said Nur Nobi, one of them.
It had a large wound in its lower part.
The authorities could not confirm the cause of its death.
Moazzem Hossain, chairman of Save the Nature, said they think the whale died at least a week ago after consuming chemical waste.
Md Amin Al Parvez, additional deputy commissioner of the district, said the departments of environment, fisheries and forest decided to bury the whale after determining its cause of death.
Deepak Sharma, president of the Cox’s Bazar Council to Preserve Forest and Environment, said two whales had washed up on the beach in 1996 and 2008.