Somsak Akksilp, the director-general of the Medical Science Department, said the man was declared dead at Rajavithi Hospital at noon on Friday (Sept 18), reports the Bangkok Post.
He had worked as an interpreter at the labour office in the Saudi capital before returning to Thailand on Sept 2.
Dr Somsak did not identify the man. But the Foreign Ministry said on Sept 2 that Mad Mamin returned to Thailand that day and was admitted to the hospital for treatment.
The medical science chief said the patient was seriously ill when he was admitted to Rajavithi and he was placed on respiratory support. However, he showed no symptoms of COVID-19.
An x-ray showed his lungs were damaged, Dr Somsak said.
"This patient was asymptomatic when he was transferred to Rajavithi, but we cannot deny that he died of COVID-19," he said.
The man’s death from the disease, the first since June 2, raised the coronavirus death toll in Thailand to 59.
The total number of cases had risen to 3,497 as of Friday, the Centre for Covid-19 Situation Administration said.