Nurfika Osman, Jakarta – A team from the National Police headquarters arrived in Ambon, Maluku, on Thursday to look into torture allegations against its counterterrorism unit, as rights groups prepared to release findings from their own probe.

The antiterror unit, Densus 88, was accused by Human Rights Watch and Amnesty International of torturing detainees, following the death on Monday of a political prisoner.

Yusuf Sipakoly, 52, was sentenced to 12 years in prison for treason, after he helped unfurl the banned South Maluku Republic (RMS) flag during a visit by President Susilo Bambang Yudhoyono in Ambon in 2007.

Yusuf's family and rights activists said he was severely beaten while in custody and was not allowed to receive medical treatment despite his failing health and need for dialysis.

However, National Police spokesman Insp. Gen. Marwoto Soeto denied these charges. "There was never any torture. And our team went [to Maluku] to prove that the allegations are false," Marwoto told the Jakarta Globe on Thursday.

"Only the [nongovernmental organizations] are making the claims," he said. "How can they say Densus 88 tortured prisoners if they did not witness it themselves?"

Amnesty said in a statement that the maltreatment of Yusuf in jail "violated Indonesia's obligations under international human rights law."

"The denial of medical care for [Yusuf] also violates the guarantee of the right to health in Article 28H (1) of the Indonesian Constitution," the London-based group said.

Meanwhile, the Australian government, which along with the United States provides Densus 88 with millions of dollars' worth of equipment and other assistance yearly, has expressed concern over the issue but says any investigation must be carried out by Indonesia.

Separately, the Jakarta-based Commission for Missing Persons and Victims of Violence (Kontras) said it was preparing to release findings from its own investigation, including a list of police officers suspected of torturing prisoners. Haris Azhar, deputy chairman of Kontras, said their initial findings confirm the torture claims.

"Our team on the ground carried out a thorough investigation, particularly among detainees being held for subversion in relation to Yudhoyono's visit to Ambon," he told the Globe on Thursday.

"We can't publicly announce the names of the suspected perpetrators," he said. "However, we can say that they include [officers] from Densus 88 and from the Maluku Police."

Haris says political prisoners "undergo a drastic change in their health condition" from the time of their arrest and that many often end up hospitalized. "Everything gets worse. They are denied access to legal assistance or to their families. The prisoners are isolated."

He said Kontras tried getting the Maluku Police to confirm the torture allegations, to no avail. "They only said that the cases in question were handled by Densus 88, and so they don't know anything about them," he said.

Meanwhile, a lawyer from the Maluku People's Advocacy Team named two officers who had allegedly tortured detainees.

Semuel Wailaruny told the Globe on Thursday that Frans Siahaya, deputy head of the Ambon subprecinct police, and De Fretes, the commander of Densus 88 in Ambon, were among the officers who allegedly exerted violence on prisoners.

"They tortured 15 people in Ambon's Nania [Prison] and six at Saparua Penitentiary," he said. "De Fretes was the one [who] signed the letter authorizing the torture," he added.

Semuel also said one of the prisoners, Yonias Siahaya, was left paralyzed after he was severely beaten by members of the counterterrorism squad. "He was blindfolded while the Densus 88 officers beat him," he said. "Now he can't even talk."

The officers reportedly covered up what they did by telling Yonias's family that he had been incapacitated by lung disease. "The victim never had a history of lung disease [in] his life," the lawyer said.