An Australian tourist was knocked out by motorcycle riders who stopped him from allegedly attacking a transgender sex worker in Thailand.

The holidaymaker in his mid-50s reportedly went on a rampage after refusing to pay the prostitute named Panya, 38, for spending the night with him in 'Sin City' Pattaya.

Footage shows the Aussie, whose identity was not disclosed by police, chasing the terrified ladyboy around parked motorcycles early morning on Wednesday, July 23.

Two passing motorbike riders later intervened and he allegedly assaulted them as well. One of them retaliated with a punch to the face, knocking the rampaging man unconscious.

Police arrived in the Soi Buakhao area of the city following a report at 4:06 pm local time. They found the tourist lying on the pavement and bleeding from his head. He was rushed to a hospital for treatment.

The motorcycle drivers remained at the scene to give their statements.

One of them said: 'They were arguing about him not paying for the service. I was watching my senior who was trying to stop the argument. Then, the man approached and threw a punch which also landed on me. After that, we fought back against him.'

Panya said she had been drinking with the tourist all night, but he refused to pay her when she was about to leave.

She said: 'I went out with the foreigner but he was drunk and acting foolish, so I didn't want to stay with him. He kept trying to follow me.

'As for the motorbike riders, they didn't know what was going on. They just tried to step in and stop him but he grabbed a chair and began chasing them. Things spiralled out of control after that.'

Police said they will collect CCTV footage from the area as they investigate the incident.

Tourists are regularly attacked or caught up in crime, leading Pattaya to be dubbed 'Sin City'.

Embarrassed officials in the central government have launched tourism initiatives to attract families and rebrand Pattaya as a safe destination.
Authorities have also introduced safety measures, such as improved lighting and CCTV.

Despite some success in cleaning up the town's image, alcohol and sex remain its biggest draws, often leading to a high rate of crime and accidents.