PHUKET: Thieves who snatched a gold necklace from a woman as she walked through Phuket City last night fled into a canal . . . and straight into the arms of a waiting policeman.

Pitchaniya Kladmee, 50, general manager of the Phuket Merlin Hotel, was walking along Montri Road near the Phuket Post office when two young men snatched her necklace and rode off on a motorcycle.

Khun Pitchaniya remembered the number plate and relayed it to police. Soon after, a patrol spotted the motorcycle parked in Damrong Road, about two kilometres away.

Nearby residents said they'd seen the two men jump into Bang Yai Canal.

Soon after, two men emerged from the canal in Thepkasattri Road. Dripping wet, they hailed a passing pickup - and were horrified to discover there was an out-of-uniform policeman at the wheel.

The pair tried to flee, but did not get very far.

Preeda A-dam, 25, and Somsak Phuangjaroen, 23, told police they both worked at Royal Phuket City Hotel where one was a Chinese food cook and the other worked in the bakery.

They said they had been drinking and decided on the spur of the moment to grab the necklace.