A dead Bryde's whale weighs about 11 tons was washed ashore in Phra Samut Chedi district of Samut Prakarn province.

The whale is 11 metres long. It was found by residents near the Phra Chulachomklao fortress shore.

It was not known the cause of death of this sea mammal but locals said they spotted the dead whale in the sea a few days earlier but could do nothing because of its size.

It was until yesterday that the dead whale was washed ashore.

Officials from the Marine Resources Research and Development Centre in the Gulf of Thailand have inspected the body of the whale but could not find a cause yet.

They have collected samples of its skin tissues and fin for laboratory test before the exact cause could be established.

But an assistant village headman Wisanu Kengsamut said local people have sighted the dead whale on Sunday at the shore near the navy prison.

He went to inspect the whale with the centre officials by boat but could not get near because the area is a shell farming which has lots of poles and therefore could not drag it out.

He said he has to wait until the wind and waves washed it to shore.

But as he noticed the whale was decomposed and might have died two weeks ago.

He also said in the Gulf of Thailand near Samut Prakarn there are about 50 Bryde's whales wandering for food.

This dead whale was the second dead whale that was washed ashore in the past seven years.