The Public Health Ministry has taken possession of the body of a British man who died in Phuket to determine whether he had Ebola.
Authorities are also monitoring some 25 people who came into contact with the man for any symptoms of the deadly virus.
Disease Control Department director-general Sopon Mekthon said the man's body was being kept at a state-run hospital under the ministry's supervision pending the results of blood tests, which are expected today.
The man's body was discovered at a condominium in tambon Patong, Kathu district, on Thursday.
Police alerted health authorities after finding the man had suffered a nose bleed, one of the symptoms of the Ebola virus.
The Briton's identity has not been officially revealed, but health authorities said he had arrived at Phuket International Airport from Lagos, Nigeria, one of the countries where Ebola is a risk, on Oct 7.
The man had stayed at the condominium on Phra Baramee Road since his arrival in Thailand.
On Oct 15, he fainted while walking on a beach and was taken to a local hospital, where a doctor found he had a record of heart disease.
The man's symptoms were not consistent with Ebola, so he was allowed to return home.
Dr Sopon said blood samples have been sent to the Department of Medical Science and Chulalongkorn Hospital to determine if the man had contracted the Ebola virus.
He said the ministry would monitor the health of the 25 people who came into contact with the man for the next 21 days.
He said the condominium room where the body was found has been sealed off and disinfected. A medical team from the ministry and local health authorities were also due to join the investigation.
Dr Sopon said the body will be handed over to police for an autopsy if the test for Ebola returns negative.
The DCD director-general said the Health Ministry has been taking measures at all points of entry into the country to screen for Ebola.
Of the 2,415 people who have been placed on the ministry's watch list, none have shown any symptoms of the deadly virus, he said.
The ministry monitors all people coming from high-risk countries for 21 days.
Public health permanent secretary Narong Sahametapat said authorities have followed international health guidelines in handling the suspected Ebola case.