Farouk Arnaz – The death of a suspected militant while in the hands of police has added to concerns about torture and ill-treatment by the country's elite counterterrorism unit, which is already under fire for killing suspects during operations.

The detainee, identified Budi Untung Santoso, aka Khidir, died a day after he was arrested in Soreang subdistrict, Bandung, on Sunday. A group of lawyers calling themselves as the Muslim Defenders Team (TPM) has raised concerns because bruises were found all over the corpse.

"His relatives are banned from contacting us," TPM member Achmad Michdan said on Tuesday. "What happened? Was he tortured? We demand answers and we will find out."

He said TPM would bring the case to the attention of the National Commission on Human Rights (Komnas HAM).

The death comes on the heels of concerns over recent operations led by the National Police's Densus 88 unit, in which at least 28 suspects were shot dead.

"The increasing fatalities and reported torture by the squad really undermines its shining achievements," said Poengky Indarti, executive director of rights group Imparsial.

"Whenever we have a chance to applaud its work, an incident like this happens and prevents us from doing so."

"I am wondering if those officers ever learned about the basic legal principle of the presumption of innocence. It should apply in any legal measure, including in counterterrorism operations," she said. "And they certainly need to learn a thing or two about human rights principles."

Poengky said police officers found to have tortured suspects must be held accountable. "Many lives have been taken for insufficient reasons and the blatant torture can no longer be tolerated," she said.

Police immediately denied any suggestions of torture, saying that the 48-year-old detainee died of a heart attack.

"He was being taken to a vehicle when he suddenly fainted," said Brig. Gen. Musaddeq Ishaq, head of the National Police's medical unit. "He was transported to Bhayangkara Hospital in Bandung but couldn't be revived."

An autopsy was performed on Monday evening and the cause of the death was determined to be a clogged artery, he said, adding there was no bruising on the body except for the stitches that were part of the autopsy.

"We have internationally renowned forensics experts," he said. "We are bound by professional and medical ethics. Even the police chief cannot interfere in our work."

A picture of the detainee has not yet been released to the public. The charges against Budi were unclear, but police have said they seized a pistol and ammunition from him when he was arrested.

[Additional reporting by Heru Andriyanto.]