A Swedish tourist was robbed at his hotel in a coastal party town in Thailand.

Par Mikael Markusson, 63, had forgotten to lock the door to his hotel room in the notorious 'Sin City' Pattaya on March 27.

He returned past midnight after a night of partying, only to find the room in disarray and his iPhone 15 missing.

Hotel employee Akkaradech Pokket, 37, accompanied the tourist to file a report at the police station.

Police Major Itthikorn Saikrathok of the Pattaya City Police Station said: ‘Investigators inspected security camera footage in the area and collected more evidence to track down the suspect for legal action.'

CCTV footage shows the suspect, described by police as a 'well-dressed man', trying to open doors on the hotel's second floor. He successfully entered the Swedish tourist's room upon finding it unlocked.

Akkaradech said: 'The man is the same suspect in another theft at the hotel. He broke into the room of a guest, Kritsana Sinet, and stole a piggy bank with 2,000 Baht, a hair dryer, a fan, and a hair straightener.'

Police said they were hunting the alleged thief.

Former fishing village Pattaya became popular with American troops on 'rest and relaxation' breaks in the 1950s and 1960s when the U.S. military had bases in Thailand while fighting Communism in Vietnam. Rural families are said to have even dressed their sons as women to cash in on the gold rush.

The handful of bars in the coastal town quickly grew and it is now the world's biggest sex holiday destination, with round-the-clock prostitution and drugs - a modern-day Sodom and Gomorrah rife with crime and debauchery.

Government chiefs have attempted to clean up the city but regular violence, depravity and claims of corruption continue to blight its reputation.