Kasper-Ansermet is the second judge to leave the tribunal over the cases, along with a number of important staff members.
A former minister of commerce for the Khmer Rouge said soldiers and civil servants of the Lon Nol government were considered “enemies.”
Saloth Ban, 67, told the court that he had lived in fear of the “terrifying” regime as secretary general of its foreign ministry.
Saloth Ban has been on the stand all week at the UN-backed court describing inner workings of the regime.
His testimony corroborates that of convicted torture chief Duch, as prosecutors seek to tie Ieng Sary and two more leaders.
Keat Chhon is among six senior government officials who have refused to appear before the tribunal.
The courier, Sot Troeung, linked Nuon Chea to the torture center Tuol Sleng in testimony Thursday.
Sot Troeung, who is 62, told the court he carried letters from Nuon Chea to the head of Tuol Sleng prison, Duch.
Im Chaem did not say who had asked her to retire, but she said her name was withdrawn from a candidate’s list.
Duch told the court Nuon Chea ordered him to execute prisoners at the facility, known to the Khmer Rouge as S-21.
A tribunal spokesman said the list of witnesses who will testify remains confidential.
Defense attorneys have said that the woes over the two cases highlight corruption in the tribunal’s judicial process.