A British backpacker is facing life in prison after he was arrested for selling drugs on Thailand's notorious Death Island.

Andrew John Brett, 36, had allegedly been peddling ecstasy and LSD to other tourists at the Ecco Bar on Koh Tao island in the southern province of Surat Thani.

Police launched an investigation following a tip-off from a concerned patron that the Brit was distributing drugs at the bar.

They tracked his activities for five months and finally arrested him on his way to the establishment on February 29.

Officers allegedly found 0.54 grams of ecstasy in a plastic bag, 25 ecstasy pills, and 75 LSD sheets, known locally as 'magic paper', among his belongings.

Police said Andrew left his apartment every day at 8 pm to sell the drugs to customers at the Ecco Bar, a short walk from Sairee Beach where Brit backpackers Hannah Witheridge and David Miller were bludgeoned to death on the island in 2014.

A police spokesman said that the case had been kept confidential for several months. They later said that they had been orders to 'suppress the case' in order to protect the notoriously mafa-like island.

The police officer, who was too afraid to be named, said: 'The suspect admitted that all the narcotics found belonged to him. He said he sold ecstasy pills to tourists for 1,000 baht each, while the LSD paper was sold at 100 baht each.'

Andrew was charged with possession of Category I narcotics for distribution. He now faces a punishment of up to life imprisonment or the death penalty, depending on how severe judges deem the case.

Koh Tao was dubbed Death Island following the murders of British backpackers Hannah Witheridge and David Miller in 2014. Previous cases of tourists deaths emerged and there have been a number of unexplained deaths of tourists since.

Authors, documentary makers and researchers have blamed corrupt Thai police and a powerful clique of local families that control the island for covering up the murders.

Hannah Witheridge and David Miller died on Koh Tao on September 15, 2014. They are believed to have been battered to death by the son of a prominent local family on the idyllic island before corrupt Thai police framed two innocent Burmese workers Zaw Lin and Wai Phyo.

Dozens more unexplained deaths of tourists on the island later emerged, causing it to be given the chilling moniker Death Island.

However, local police have since made efforts to censor any negative cases emerging from the idyllic island, with a handful of local families that have lived there for decades benefiting financially from its attractiveness to backpackers and scuba divers from around the world.