Police will investigate how a sick 41-year-old male driver died after being held at Yannawa Police Station in Bangkok for two hours after police mistook his illness for drunk driving.

Metropolitan Police Division 6 had formed a committee to investigate the case.

Ms Manao (surname withheld), the girlfriend of the dead driver, Krit Thammol, 41, will take legal action against officers at Yannawa Police Station.

Krit had provided an airport transfer service to passengers at Suvarnabhumi Airport. He suffered from a stroke.

Ms Manao said Krit had a severe headache and vomited after dropping off passengers at a hotel in Yannawa district in Bangkok on July 13.

He called Ms Manao who told him to go straight to a hospital. 

However, he was struggling to control his car on his way to the hospital as his symptoms became worse, resulting in his car crashing into several motorcycles, said Ms Manao.

After the crash, he was held at Yannawa Police Station and accused of drunk driving.

She said Krit fell unconscious at the police station and was sent to hospital where he died three days later.

Ms Manao found that her boyfriend was held at Yannawa Police Station for almost two hours, adding that if he had been sent to the hospital earlier, he might have survived.

A hospital test conducted yesterday confirmed that Krit had not been drinking.