Amnesty International has accused Thailand's military government of targeting suspected insurgents, political opposition and individuals from the most vulnerable sections of society. The junta was allowing a "culture of torture" to flourish in the country, the rights group said.

In its report, 'Make Him Speak by Tomorrow: Torture and Other Ill-Treatment in Thailand', Amnesty said it had documented 74 cases of torture and ill-treatment by the police and soldiers.

Amnesty said martial law and post-coup decrees had allowed authorities to detain some people incommunicado at unofficial sites for up to a week, the period the military is authorised to hold detainees in official places without contact with the outside world.

Many interviewees who spoke to Amnesty said they faced severe abuse and ill-treatment while in detention. They reported allegations of beatings, choking with plastic bags, strangulation, waterboarding and electric shocks.

Dozens of those who have been critical of the government were thought to have been arrested following a coup in 2014. However, the exact number of detainees has not emerged yet.

The military, which took over following the coup, has denied all allegations of torture, always maintaining that it stepped in only to prevent violence and restore peace after protesters targeted the government.

One of the victims, who were arrested soon after the coup, said his head and face were covered with a plastic bag until he fainted. A bucket of cold water was allegedly poured on him. "They applied electro-shock to my penis and chest. I was restrained, my legs tied, and my face covered with tape and a plastic bag," Amnesty quoted him as saying.

He described it as "the worst day" of his ordeal and said he pleaded with his persecutors to kill him instead of torturing him.

Rafendi Djamin, the rights group's director for Southeast Asia and the Pacific, said: "Empowered by laws of their own making, Thailand's military rulers have allowed a culture of torture to flourish, where there is no accountability for the perpetrators and no justice for the victims."

Rejecting the accusations, General Sansern Kaewkamnerd, spokesman in the Prime Minister's Office, told Reuters: "Our investigations into such allegations have shown no indication of torture, I have seen no indication of torture and the Thai people have seen no indication of torture."

Amnesty was due to release its report at a news conference in Bangkok on Wednesday (28 September), but it had to call off the event after reportedly receiving a threat of arrest from a few "men wearing jackets with tags identifying them as ministry of labour officials".

Omar Waraich, media manager for the group in Asia, said Amnesty was cancelling the event although it did not receive any official communication from the government.