Purges and alleged rifts between units at the Trapeang Thma dam were raised in testimony at the Khmer Rouge tribunal yesterday, as an anonymous witness was probed on the arrests of senior figures and civilians at the worksite in his second consecutive day of testimony.

Identified as “2-TCW-918”, the former mobile work unit commander was stationed at the dam in June 1977 at the time of the arrest of its notorious overseer, Ta Val. However, under questioning by the prosecution, the witness denied any knowledge of the motives or chain of command behind Val’s purge or those of other cadres from the Northwest Zone.

“I was wondering myself why those cadres were arrested, including cruel and kind cadres,” he told the court. “So I did not understand the reasons behind their arrest.”

The prosecution cited an interview from the Documentation Center of Cambodia (DC-Cam) in which an interviewee claimed to have seen a list of 100 people at Trapeang Thma, with 2-TCW-918’s name one of only two not slated for arrest.

Yesterday’s witness said he had seen the same list but didn’t know why those on it had been fingered for arrest, or why he had been excluded.

However, his accounts appeared to conflict with his own previous testimony to DC-Cam in June 2011, in which he inferred that Ta Val may have been accused of treason by units from the Southwest.

As noted by Nuon Chea defender Victor Koppe yesterday, the witness had told DC-Cam that Southwest cadres who arrested Val “said he was a traitor”.

Further pressed on the question of the transfer of weapons for a potential revolt by Northwest mobile units at the dam, he denied being privy to any such plans.

“I was not in a position to know about who had an idea to rebel,” he told judge Jean-Marc Lavergne. “I myself was thinking about the fact that they were all part of the revolution.”

Describing conditions at the worksite to civil party lawyers, 2-TCW-918 testified that forced marriage was a common penalty for those accused of so-called “moral offences”.

However, he declined to comment on whether the treatment of workers deteriorated following the arrival of units from the Southwest, noting that he was restationed to a nearby fishery site shortly afterwards.

As to whether workers generally feared for their safety, he stated that “I didn’t know about their feelings in my unit.”