Meas Lay Hou was relieving herself in the forest that edged the Khmer Rouge’s “January 1 dam” worksite when she noticed a wooden cage the length of a tall man; inside, she recognised a member of her work unit who had been removed for re-education.

She never saw the man again, she told the Extraordinary Chamber in the Courts of Cambodia (ECCC) yesterday.

“We were afraid if we reported what we saw, we would be taken away and killed,” she told the court during her first day of testimony with the support of a mental health counselor from the Transcultural Psychosocial Organization (TPO).

Even while relieving oneself, she said, armed militia stood watch.

Lay Hou’s testimony affirmed and heightened the atmosphere of fear, oppression and illness pervasive at the worksite in Kampong Thom’s Baray district, which the court first heard described last week by witnesses Or Ho and Pech Sokha.

While previous accounts reported workers carried loads of soil and stones for 13 hours each day, Lay Hou called the site “the hot battlefield” where workers laboured for 19 hours daily – woken at 3am and working until midnight, with just two one-hour gaps to eat small meals of morning glory soup.

“We had no strength and energy but we had to try and carry earth, otherwise we would be taken for [re-education],” she said.

Lay Hou also confirmed, despite objections from the defence, that the Baray Chorn Dek pagoda was used as a killing centre. She remembered seeing trucks and ox-carts drive people to the pagoda and the music that would play.

“Later on, I learned when the loud speaker was playing music, it meant people were being killed,” she said. “Then I would avoid the area.”

The court also heard oral arguments from the prosecution and defence who debated whether confessions obtained under duress and torture might be admissible in the case – something prohibited by the United Nations Convention Against Torture.

“Saying that under certain circumstances torture is justified is an American argument, made by [former US vice president Dick] Cheney at certain prisons,” said defence lawyer Victor Koppe, who hopes to use the evidence in court.

“We would not make that statement.”

The court has yet to rule on the use of evidence obtained through torture; Lay Hou’s testimony will continue today.