Jakarta, Indonesia (CNN) -- A thin man with graying hair lies on his back, completely naked on a dusty road. His legs and arms are bound and his body suddenly contorts in pain. A man stands above him and pushes a smoldering piece of wood against his genitals.
He cries out in pain, but it doesn't stop his tormentors.
"Where did you put the weapons? Show us where the weapons are!" demand the men, one of whom is wearing military fatigues.
A few feet away, a younger man is lying in a similar position but clothed. The same group of interrogators move over to him, hold a knife under his nose and then repeatedly slap his face. They also ask him questions about weapons and the whereabouts of rebels.
The scenes were recorded on a cell phone in Indonesia, fueling shock and condemnation from human rights groups around the world who believe the video is possible evidence of Indonesian armed forces torturing those seeking independence from Indonesia.
The video is "the latest reminder that torture and other ill-treatment in Indonesia often go unchecked and unpunished," said Donna Guest, the Asia-Pacific deputy director for Amnesty International.
CNN obtained a copy of the video from an international nongovernmental organization, but the network has not verified its authenticity.
Indonesian military spokesman Aslizar Tanjung told CNN that there is an "intensive investigation" being launched regarding the video.
"We need to verify the authenticity of the time, place and activity of what is shown in the video," he said. "The soldiers are trained and educated according to the standards of procedures. They should be aware of their duties, responsibility, [and] provided with knowledge of human rights, of what they can and cannot do in the field.
"Hopefully, the investigation won't take too much time so we can soon clarify to the people what really happened. So far this is only an allegation that there is a certain group who did the torture. We need to legally prove it."
The video is believed to be from the Indonesian province of Papua, nearly 3,500 kilometers [2,175 miles] east of the capital, Jakarta. Papua has long had a low-level insurgency that demands independence from Indonesia, saying the government is trying to take its land to steal resources.
Papua is home to the largest gold mine in the world, operated by the U.S.-based Freeport-McMoRan Copper & Gold, but members of the freedom movement say locals have not received fair economic benefits from any of the mining operations on their homeland.
The indigenous Free Papua Movement was established in 1965 to push for secession. The group disputed the terms under which Papua became a part of Indonesia that year.
Human rights groups say that while they haven't determined the authenticity of the video, they have clues that the tormentors are members of the Indonesian armed forces.
For example, the weapon being used in the video appears to be a standard military issue and the questions posed by the interrogators are consistent with those of Indonesian security forces, said Phil Robertson, deputy director of Human Rights Watch's Asia division.
"There is a lot of circumstantial evidence that would lead us to believe that this may be the security forces but we can't authenticate that," Robertson told CNN, adding that that's one of the many reasons a complete investigation is needed.
However, the group is concerned that the government will let the case linger without a resolution.
"The major concern is that this is going to be another whitewash, that this is going to be an internal military investigation similar to many others that we have seen," Robertson said.
Another video surfaced this year showing another gruesome scene that is also believed to have taken place in Papua. It shows a disemboweled man, who has been identified as Papuan political activist Yawan Wayeni, in the jungle.
Men in police uniforms are seen sitting and standing near Wayeni as he suffers. The uniformed men taunt him, saying, "You are never going to get freedom as long as the soldiers are here."
Wayeni is barely audible, but says "freedom." He eventually dies from his wounds.
Police denied allegations that they disemboweled him, saying he was injured in a firefight. No officer was disciplined in that incident.