Surveillance cameras showed that the man, aged 32, took the escalator from the third to the fourth floor before the incident took place at 6.25am.

Medical staff tried to revive the man and he was taken to Samitivej Srinakarin Hospital, according to the Bangkok Post, but he died from his injuries.

Local police believe the man jumped from from the fourth floor and that the incident was one of self-harm.

"We checked the CCTV and there was no one else with him, he walked alone from the third floor to the fourth floor... we believe it was his intention to harm himself, that nobody threatened him," said Police Lieutenant Colonel Kawee Ratana, according to the ABC.

The airport had installed 2.5 metre high glass walls inside and outside the terminal after past similar deaths. Kittipong Kittikachorn, the airport's safety manager, has ordered engineers to consider erecting additional safety walls.

The name of the man, who also has Irish citizenship, has not yet been made public.

In a separate incident, a 49-year-old Australian man died when his rented motor-cycle and a 10-wheel truck collided on the Thai resort island of Phuket. The man had rented the motorcycle early Thursday and was due to return it on Friday.

A helmet was found beside the body.

The man, who was from New South Wales, was staying in a hotel in the Patong tourist district.

Motorcycle accidents account for many of hundred of deaths each year on Phuket's roads, including many Australians. An average 20,000 Australians holiday on Phuket each month.

Twenty year-old Victorian woman Emily Collie was killed when two jet-skis collided off a Phuket beach in February.

Her partner, 22-year-old Thomas Keating, was handed a one-year prison sentence - suspended for two years - in a Phuket court last week after pleading guilty to reckless driving causing death.

He said the accident happened after he was blinded by the sun. Mr Thomas has been allowed to return home.

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