Shocked locals found a 40ft long whale washed ashore in a mangrove forest yesterday (January 26) morning.
Fishermen noticed the huge 15 tonne carcass which emerged from the Gulf of Thailand in Samut Prakan, 30km south of Bangkok.
Researchers from the Marine and Coastal resources research centre arrived to inspect the huge Bryde's whale.
They said the sea creature was a six-year-old female which is believed to have been dead for five days.
Chalatip Chanchompu, director of the country's sea research centre, said marine biologists will cut the whale's tissue to identify her sub species.
They will then perform a post-mortem examination after the body has been transferred to a patch of open land.
Chalatip said: "We could not identify the cause of her death yet. First we will examine her tissues to determine her subspecies.
"The body will be moved to empty land where it can be operated on fora a post-mortem examination, to confirm how she died.''
The scientist added that the centre will keep the whale's bones for educational purposes.
She said: "The whale's body will be buried but we will gather her bones and keep them for research at the centre. The tissue will decompose in around two years."