
Akaradej Tankae, 31, confessed to police that he had killed Charlotta Hanna and then fled to Song Island, also known as Victoria Point, in neighbouring Burma, police said.
Police issued an arrest warrant for Akaradej on Tuesday and posted a Bt100,000reward for information leading to his arrest.
According to policem Akaradej said he killed Hanna, 27, because he was suffering family stress.
Hanna was found hacked to death on Mai Khao beach on the island, where she had rented a bungalow. Police said they believe she was killed late Saturday or early Sunday while taking a walk on the beach.
Tourism and Sports Minister Weerasak Kohsurat visited the island Monday to speed up a resolution of the case, which has raised concerns about security for female visitors to Thai beach resorts.
Weerasak, who assumed his post February 6, reportedly suggested passing out whistles to all female tourists on Phuket as a means of protecting them during midnight strolls on beaches.