The carcass of a humpback whale washed ashore on the Himchhari beach adjacent to Cox's Bazar-Teknaf marine drive on Friday morning, reports UNB.
Locals found the rotting carcass when the tide was receding.
"We suspect that the whale died a week ago. Samples from the carcass have been collected for tests. The reason behind its death can be known after a necropsy," said SM Khalequzzaman, the Cox's Bazar district fisheries officer.
The 44 feet long whale is believed to be about 17 years old, said marine biologist Jahirul Islam.
Khalequzzaman said this species is seen in the Bay in the south-western part of the Sundarbans.
Additional deputy commissioner Amin Al Parvez told reporters that they would try to determine the cause of the whale's death and bury it as soon as possible.