A sperm whale, 18 meters long, died after being washed up on a beach in Bali, BTA reported, citing representatives of the Indonesian island's environmental protection services.

The multi-ton whale was found alive and returned to the water by authorities and local residents.

A few hours later, however, the sperm whale appeared on another beach, where it died with no visible injuries.

An autopsy is scheduled for today.

"We are still trying to establish the cause of death. We want to get a scientific explanation to know whether it is pollution or plastic waste," authorities said. 

Fishing nets and plastic bags were found in the stomach of a washed-up sperm whale in Hawaii

Vets were expected to visit the site to determine the cause of the sperm whale's death.

He will be buried in the next few days.

The police blocked access to the beach to prevent the theft of meat or parts of the animal.

Sperm whales often come close to beaches when they are sick or dying, experts say.

In 2018, a sperm whale was found in Indonesia having swallowed more than 100 cups and 25 plastic bags - a dramatic illustration of the scale of the marine plastic waste problem facing the Southeast Asian archipelago.

Indonesia is considered to be the second largest source of plastic waste in the sea after China.

Bali island

Sperm whale