Crocodiles are seen in and outside a pond at the farm where a woman committed suicide in Samut Prakan, outside Bangkok. 

AFP/Bangkok

A 65-year-old Thai woman has committed suicide by leaping into a pond of crocodiles at a farm popular with tourists on Bangkok's outskirts, police said on Tuesday.

The incident occurred during opening hours at the farm which doubles as a zoo and draws visitors who can feed the deadly reptiles from a walkway.

The woman jumped on Friday from a resting point on the walkway into the middle of pond - which contains hundreds of adult crocodiles, Preecha Iam-nui of Samut Prakan police said.

"Her sister said the victim was suffering from stress and depression," Preecha added.

The farm is an hour outside Bangkok.

Safety rules are often lax at Thai tourist attractions, which include tiger and crocodile farms.

The Samut Prakan farm fences are just a few feet high to allow visitors - including children - to feed the reptiles.

Trainers also perform with the creatures, lying on top of them or thrusting their heads and arms into the reptiles' open jaws.

Myanmar men questioned over murder of British pair

Thai police on Tuesday questioned three Myanmar men over the murder of two British tourists on the southern resort island of Koh Tao, as their bodies were due to arrive in Bangkok for forensic tests.

David Miller, 24, and Hannah Witheridge, 23, were found naked and beaten to death early on Monday near a beachside bungalow on the island, a diving hot-spot near Koh Phangan in the Gulf of Thailand.

A bloodied hoe was discovered 35 metres from the murder scene.

"Three male Myanmar migrant workers are under police detention for investigation," southern regional police commander Panya Maman said, without providing any further details.

A second officer said police were not looking for a British man who had travelled with Miller, contrary to UK media reports.

"All of the British nationals are now on their way home," provincial police chief Kiattipong Khawsamang said, adding they had been "cleared" as suspects.

Neither officer was able to confirm Thai television reports that police had seized an iPhone and blood-stained jeans after raiding rooms used by the Myanmar suspects.

Thai authorities frequently accuse migrants from Myanmar and Cambodia of committing crimes in the kingdom, where they make up a vast, poorly-paid and low-status workforce.

The bodies of the victims, who arrived in Thailand on August 25, are being driven the 500 kilometres from southern Surat Thai province and are due in Bangkok later Tuesday for forensic tests.