BANGKOK (AFP) - A translator for two Uighur men accused of a deadly Bangkok bombing was remanded in custody on Friday (June 3) for drug possession, further complicating a murky trial that has failed to answer key questions about the unprecedented attack on Thailand.

Sirojiddin Bakhodirov was arrested this week with small amounts of marijuana and crystal meth. On Friday, a Bangkok court extended the Uzbeck national's remand, according to police.

But Bakhodirov, who is the only Uighur translator at the Bangkok bomb trial, told AFP by phone the drugs were planted on him as punishment for helping Thailand's Uighur community.

The mostly Muslim ethnic minority faces persecution and discrimination in their homeland in northwestern China, forcing many to flee and often use Thailand as a transit country.

Two Uighur men were arrested over the August 2015 bombing that killed 20 people - mostly ethnic Chinese tourists - at Bangkok's Erawan shrine.

"I am innocent, they set me up," Bakhodirov told AFP of his drug charges. "They don't want me to translate because I help the Uighur community".

Police have denied the framing allegations.

"It happens to be that (the suspect) is related to a high-profile case. That is why it is getting attention from the public," said deputy police spokesman Krissana Pattanacharoen.

Bakhodirov told AFP army officers interrogated him about Uighurs in other parts of Thailand after his arrest.

The two Uighurs accused of bombing Bangkok deny the charges and one of the suspects, Bilal Mohammed, says police tortured him into making a confession he later retracted.

The most recent court hearing saw Bakhodirov translate testimony from a sobbing Mohammed as he accused Thai captors of beating him and denying him halal food in prison.

A month before the bombing, Thailand's military government forcibly deported more than 100 Uighurs to China.

The move inflamed rights groups and has fed speculation that the bombing was plotted as revenge on a kingdom which had been a key transit route for the minority.

Thai authorities have rejected the theory and insist the attack was in retaliation for a crackdown on a people-smuggling gang.

But they have yet to catch a number of other suspects - many of whom, including the alleged mastermind, are believed to be overseas.