An Iranian man accused of sexually groping a woman taxi-motorcyclist on Sunday while riding pillion was arrested at Suvarnabhumi airport on Tuesday morning. 

The woman, who gave her name as Nampueng, 40, told police she picked up the man at the Queen Sirikit National Convention Centre in Bangkok on Sunday evening. He had booked her bike using a phone app.

During the trip, the passenger started to touch her body and tried to put his hand inside her pants, Ms Nampuemg said. She decided to drive to a nearby police station.

Instead, the man told her to go back to where they came from. She headed back, but the man continued to grope her. 

She went to a nearby police booth at Witthayu intersection, but it was empty, so she called out to passersby for help.

The Iranian told her to stop shouting and said he would pay for the ride. When she continued to call for help, he ran away without paying. Some people tried unsuccessfully to catch him, she said.

She later filed a complaint with police, who looked at CCTV footage and confirmed the man's identity.

The suspect was arrested at the Suvarnabhumi airport immigration desk as he was about to leave Thailand around 1.47am on Tuesday.

Ms Nampueng said she had been an app rider for about two years. This was the first time she experienced such behaviour. She would stop driving for a while, she said.