Muhibbudin says he is not a GAM member but was still held for 20 days. "In one night 10 TNI people kicked me, and abused me," he told Ms McCulloch.
Indonesian forces are continuing to rape, torture and murder Acehnese despite signing a peace treaty this year, according to a British researcher.
One of the most disturbing accounts was of Muhibbudin, a young Acehnese man with a massive scar on his torso - he says this is where his kidney was forcibly removed to give to an Indonesian soldier.
Muhibbudin, 23, is also deaf and has trouble speaking - legacies, he says, of repeated beatings around the head by the TNI, the Indonesian military.
Kidney
His trouble began when he was detained on suspicion of belonging to the rebel Free Aceh Movement (GAM) which has been fighting for independence from Indonesia for the last 24 years.
Muhibbudin says he is not a GAM member but was still held for 20 days. "In one night 10 TNI people kicked me, and abused me," he told Ms McCulloch.
"I was afraid they would kill me. I was shot and I was burned on the legs.
"After 21 days they took me to hospital where a doctor took one of my kidneys to give to a military person."
Muhibbudin says he was repeatedly beaten and given almost nothing to eat. A photo apparently taken at the end of his ordeal shows a distressingly emaciated man, covered in scars.
"Please tell the world about the atrocities that are happening here," he begs at the end of his testimony. "I am not the only one."
Rape
Ms McCulloch, a research associate at the Centre for Defence Studies in London, says the West has little idea of the scale of human rights abuses in Aceh.
Many accounts were from women who said they had been raped by soldiers and police.
"The military came to my house and took my husband and tied him up, then they raped me," one woman said.
"All 11 houses in the village were visited. I was one of six who were raped that day. Now I am afraid in my home. I'm afraid the military will be sent again."
Many of the rape victims blamed officers from Indonesia's elite mobile police unit, Brimob, who are drafted in from Jakarta.
Shooting
Ms McCulloch's visit coincided with a crackdown on a pro-independence rally last month in the provincial capital, Banda Aceh.
One woman she met en route to the event told how troops had shot dead her husband as the family tried to reach the rally.
"The military shot my husband in a rice field. Then they began to shoot at [our convoy]," she said. "We have no weapons, we are only farmers. They have the guns."
Many of those terrorised on the road tried to get to the rally by boat, but Ms McCulloch says Brimob forces arrived at the port and started firing - two civilians were injured.
"The government says it is rogue elements who do this, but I saw people being shot at by whole units of military and police," she added.
"Outside Banda Aceh I saw people being shot at as they ran through rice paddies for cover - none of them was armed."
Graves
No-one knows how many people died during the crackdown, but Ms McCulloch says there were repeated reports of Brimob taking bodies away.
She says a number of mass graves have since been discovered - post mortems show the victims died at around the time of the rally.
The violence between Indonesian forces and GAM rebels has claimed at least 5,500 lives.
In June the two sides signed a ceasefire, but clashes have continued.
Local rights groups say around 840 people have been killed this year - more than double the total for 1999 - and several hundred others are missing.
Rebel support
In the past the issues of independence for Aceh and support for the GAM rebels were often separate.
But Ms McCulloch believes the actions of the security forces have driven many people towards backing GAM as the only way of achieving independence.
"It is quite obvious that support for independence, or at least for a referendum to let the people choose, is extremely high," she says.
"The actions of the Indonesian forces have been completely counter-productive."