Bangkok -
Thai police called in more than 30 fishermen to take DNA samples as they expanded an investigation into the murder of two British tourists on a southern island, local reports said on Monday.
Police also said they had detained two men who were seen on CCTV footage at the time and around the area of the murders, the Thairath newspaper reported.
Police had earlier questioned migrant workers and a travelling companion of the murdered man, before DNA testing cleared them of involvement.
The murdered tourists, a man and a woman, were found on the beach last week at the island resort of Koh Tao, 350km south of Bangkok.
The couple, both 24, suffered extensive injuries to the head and neck.
In the past five years, 13 British tourists have been murdered in Thailand, out of the more than four million who visited the country. - Sapa-dpa