Prosecutors at the Khmer Rouge tribunal are requesting that alleged acts of sexual violence be added to the investigation in government-opposed Case 004.

According to yesterday’s filing from international co-prosecutor Nicholas Koumjian, forced marriages, with instances in which groups of up to 80 couples were wed in a single ceremony, rape and sexual violence outside the context of forced marriage, execution following rape and the killing of women who reported rapes are all among the new allegations.

The acts, which took place sometime in the mid-to-late 1970s during Pol Pot’s Democratic Kampuchea, were allegedly perpetrated by Khmer Rouge cadres in areas where named suspects in Case 004 “held command or political positions of influence”, according to the filing.

Though the identities of Case 004’s defendants – who have not been officially charged with a crime – are technically confidential, they were long ago revealed to be Ta An, Ta Tith and Im Chem.

It will now be up to the Office of Co-Investigating Judges to decide whether to pursue the new evidence or stick with allegations laid out in the original introductory submission in 2009.

The new evidence became available from civil party applications for the current case against defendants Khieu Samphan and Nuon Chea, and in statements from witnesses interviewed for Case 004, which has yet to come to trial. Claims of forced marriage will also be heard in the next phase of Case 002, which is expected to commence in the coming months.

The new evidence in Case 004 constitutes “crimes against humanity including extermination, murder, enslavement, imprisonment, torture, rape, persecution and other inhumane acts”, the filing says.

Court rules stipulate that supplementary submissions from prosecutors remain confidential, but they allow for an “objective summary” to be made public.

International Co-Investigating Judge Mark Harmon, who is also responsible for investigating Case 003, which was split from Case 004 and is also government-opposed, did not respond to a request for comment made through the court’s public affairs section. Harmon is believed to be flying solo on the investigations, without active help from his Cambodian counterpart, You Bunleng.

Long Panhavuth, a program officer with the Cambodia Justice Initiative, welcomed the public nature of the filing, but urged more transparency in the case, in particular more information on its progress and better access to the case file for the relevant parties.

“None of them [the suspects], including their lawyer, have access to the case file,” Panhavuth said, a restriction he called “outrageous”.

“Mark Harmon should understand his role as investigating judge,” he said. “I think that after almost two years from his arrival in the country, the public and the victims should know what is going on.”