Carmela Baranowska travelled to the remote Oruzgan province and filmed the testimony of 35 Pashtun villagers from Passau who were held in detention for up to five days this June.
Back in Sydney, the SBS reporter detailed events in a documentary aired for the first time on Wednesday and sent her evidence to the US army.
In the programme, Baranowska says US marines used the tactic of sexual humiliation similar to that reported at Abu Ghraib prison in Iraq.
Fingered and beaten
One of numerous examples, 27-year-old Afghani villager Wali Muhammad described in detail his alleged abuse by a group of 20 US soldiers.
"They fingered us, beat us and humiliated us," he says in the report. "There were youngsters as well. They took off my clothes... Fingering the anus is against Islam.
"Now that we are aware of these allegations, the commander of Combined Joint Task Force 76 has directed an inquiry into the matter"
Combined Forces Command Afghanistan
"They were all laughing and mocking. When they took me a second time they stripped me again. Yes, they took our picture."
The abuse has had a devastating effect on the village.
An older resident described how he had had to wipe off a "wetness" from his backside after he had stood naked, spreadeagled and face to the wall.
Baranowska explained the consequences of the abuse. "The Pashtuns in the Mirabad valley live in a tight-knit and culturally traditional society. The effect of removing all the men from the village has shamed them very publicly.
"With just women, children and US soldiers in the village in addition to their sexual humiliation, they have completely lost face in the community. 'It is if we were dead. We have no honour' one of the villagers told me."
Some of the villagers had even fled their homes for Pakistan through shame.
US military response
A US Central Command spokeswoman, Susan Meisner, has confirmed that 35 men from Passau were detained on 23 June and that an investigation into the alleged abuse would be made.
"Now that we are aware of these allegations, the commander of Combined Joint Task Force 76 has directed an inquiry into the matter.
"Our policies do not authorise photographing detainees in the nude ... but we do photograph detainees' faces and other distinguishing marks, such as scars," Meisner wrote in an email response to the documentary.
Baranowska described how she had originally been embedded with the US marines and was totally unaware of similar cases that she found in other villages. "I only saw what they wanted me to see," she said.
But her suspicions arose after she obtained an independent translation of an interrogation by a local tribal leader who is cooperating with US forces, Jan Muhammad.
The documentary shows a US
officer hitting his own soldiers
"He was ostensibly questioning villagers looking for Taliban sympathisers. He detained one for two days basically to show he was making progress. Once I had the transcript translated, it was clear this man was being detained for no purpose whatsoever," Baranowska said.
After her experiences in the remote province, the film-maker said she had become suspicious every time a shooting was blamed on the Taliban. She said: "The place is so remote, there are no independent observers, checks or balances -anyone can get away with anything."
Excerpts from the documentary can be viewed online at www.sbs.com.au/dateline.