Police seized six million meth pills hidden in a watermelon shipment in Thailand.

Eagle-eyed officers flagged the truck when they noticed the fruits were stacked haphazardly - indicating it was not the work of an experienced farmer - on the cargo bed at the Tha-Ngam drug checkpoint in Phitsanulok province on March 19.

They inspected the load and found a staggering six million meth pills stashed under the watermelons.

The driver Uthen Suramit, and his passenger Asadawut Kasetprasert, both 20, were pulled aside for a drug test which returned positive.

The alleged mules claimed that they were hired for 150,000 baht (3,250) each to smuggle drugs from the northern province of Chiang Mai to Ayutthaya province.

Three more suspects in a lead car that had passed the checkpoint were arrested. They were identified by police as Burmese national Jai Laengduean, and Thai natives Nattaphon Tontrong and Jirayu Laoko, both 20.

The alleged smugglers were taken to the Wat Bot police station to be prosecuted.

Police General Kittirat Phanphet, Deputy National Police Chief, said: 'This is one of the largest drug seizures in the lower northern region of the country. The officers at the checkpoint did a great job.

'They noticed the watermelons were not arranged properly. A legitimate watermelon trader would have sorted them according to their size. While being questioned about the watermelons, the arrested suspects also gave inconsistent answers.

'To stop drug smuggling from the upper northern to central regions, police are making sure their checkpoints are strict and officers are well-trained. They are watching out for smugglers who use agricultural crops to hide drugs.

'We are working hard to dismantle drug networks across the country. Investigations are ongoing to find the people behind this smuggling attempt and to prevent similar crimes in the future.'

Thailand has become a notorious hub for drug production and trafficking.

In the north of the country, the 'Golden Triangle' area shares borders with Laos and Myanmar, and has produced large amounts of opium since the 1950s but focus in recent years has shifted to the more profitable methamphetamine.

Officials believe most of the meth is produced in the Shan State of Myanmar before being distributed through neighbouring countries where prices are higher before ending up in the most expensive markets of Australia, Japan, Hong Kong, Taiwan, and Singapore.

A power struggle has emerged in Myanmar following the ousting of leader Aung San Suu Kyi, with the military coup leaders said to be heavily involved with the production and protection of meth labs, in cahoots with gangs from China.