It said it had faced “difficulties” in obtaining information from enforcement agencies, particularly the Royal Malaysia Police (PDRM).
Requests for information from the home ministry had also gone unanswered, it said.
Given the delay in the criminal investigation, it said, it had also approached the National Human Rights Commission of Thailand for cooperation.
“Suhakam is deeply concerned that the lack of progress in the criminal investigation may result in impunity for the perpetrators, and we urge the authorities to ensure that the ongoing investigation is conducted with due diligence by competent officers as the government cannot afford to be seen as sharing responsibility in the tragedy by omission, neglect and/or incapacity to act,” it said in a statement today.
On Wednesday, the New Straits Times (NST) reported that there had been massive cover-ups in the Wang Kelian graves discovered on the Malaysia-Thai border in 2015.
It said authorities had already known about the mass graves, but delayed announcing it until four months after they were first discovered.
The daily also said police had cleared the campsite where the mass graves were discovered, destroying potential evidence at the crime scenes before they were processed by forensics personnel.
It said the two-year investigation had revealed that Wang Kelian might have been part of a “massive, coordinated cover-up”.
Suhakam, which launched its own probe into the matter, praised the daily for its efforts and tenacity in investigating the death camps and expressed regret for the delay in its investigations.
“Despite these limitations and the many difficulties generated by the passage of time, Suhakam would like to assure the public that we will leave no stone unturned, and will exert all means to get to the bottom of this horrifying incident.
“Suhakam’s report will be made available to the public and to the authorities,” it added.