A British tourist is seeking help after a Thai woman reportedly stole his £21k Rolex from his apartment in Pattaya.

Steven Brown, 39, said he met the unnamed suspect at his condo in the Bang Lamung district, and they have been keeping in touch since.

On Sunday evening, the Brit brought his new lady friend back to his room and hopped into the shower, leaving the expensive timepiece on his bedside table.

However, when he emerged from the restroom, he found the Rolex watch gone and allegedly caught a glimpse of the woman fleeing from the room's window.

He said: 'She must know the value of the watch. When I took the watch off and put it on the bed, I heard her grab it while I was in the shower so I shouted.

'I called security, and she jumped out the window.'

With the help of his Thai friend Wasana Rachchom, 38, Mark filed a report with the Pattaya police and also complained to local news reporters 'to help warn tourists against criminals' in Pattaya.

Mark has sent messages to the woman pleading for her to return the diamond-set gold accessory as it was incredibly valuable and held sentimental value.

Pattaya police officers have also contacted the woman using Mark's phone, warning her to return the watch as they had CCTV footage of the theft.

Mark added: 'The watch has sentimental value to me, too. I've learned my lesson. Never trust anyone in your room.'

Thailand's current military government has made efforts to clean up Pattaya after it was dubbed the 'sex capital' of the world and a modern-day Sodom and Gomorrah.

However, the entrenched sex industry and endemic corruption have proved difficult to tame in the once-sleepy coastal city.

A large number of British ex-pats have also set up bars in the sun-drenched resort, which has become an attractive place for pensioners to retire.