One suspect was arrested and four others are being tracked down by police after the abduction of a wealthy Chinese man in Bangkok on Friday and payment of a 3.5 million baht ransom.

The victim was smuggled out of a Bangkok condominium in a plastic box and taken to Prachuap Khiri Khan.

One of the suspects is the victim's former Thai girlfriend.

Police said that a Chinese man, Yu, told Lumpini police on Saturday that he had lost contact with his 34-year-old friend, Wang Nanfeng.

On Sunday Mr Yu saw Mr Wang in a video call. He had a bruised face. He learned that his friend was abducted for a ransom. He was told there was no need to tell police because Wang would be released after the ransom was paid.

According to police, Mr Wang had a Thai girlfriend for about a year and had broken up with her three months ago. The woman knew that Mr Wang was rich and she allegedly planned the abduction with a gang of Thai men. They used an expensive car Mr Wang had bought for her to commit the crime.

The abduction occurred about 7pm on Friday. Four Thai men entered Mr Wang's condominium in Sathon area using the woman's keycard. They subdued him and tied his hands and feet and used the victim's phone to call the building security guard and borrow a cart.

The victim was then put in a large plastic box which was taken out of the building on the cart and put in the back of the woman's car. They then drove to Hua Hin district in Prachuap Khiri Khan.

They forced Mr Wang to make two money transfers - 2 million baht and then 1.5 million baht, according to police.

On Sunday the gang took Mr Wang to an eatery in Hua Hin. There, Mr Wang fought back against them, and local police arrested him for assault. Police also apprehended a 24-year-old Thai man. The others fled.

Still at large were the Thai girlfriend and three accomplices.