Court observers say the statement from OSJI and the submission of Cayley do not necessarily signal a problem at the court.
The UN-backed court’s investigating judges have come under fire in recent weeks after they made a preliminary conclusion to Case 003.
At least five key staff members have left the Khmer Rouge tribunal’s investigating judges’ office since April.
International prosecutor Andrew Cayley said in a public statement last month he would file for further investigation in the case 003.
The court has come under increased criticism of political interference and a lack of funding.
The Council is expected to announce a four-year rotation of judges and prosecutors, including retirees, on Wednesday.
Under the Khmer Rouge, Muslims were forced to break major tenets of their religion, including eating pork and frequent prayer.
The judges have also ordered Cayley to retract portions of a public statement involving Case 003.
The procession included monks from Burma, Japan and Thailand, as well as Cambodia.
Sam Rainsy alleges Hun Sen was responsible for the deaths of people sent to clear forests along the Thai border in the 1980s.
About 250,000 women were forced to marry against their wills by the Khmer Rouge, according to the film producers.
“Extraordinary Chambers” is showing at the Geffen Playhouse in Los Angeles through July 3.