In a joint statement by 66 NGOs last week, groups said they wanted to contribute meaningful input to the draft law.
Chea Vichea, a widely popular labor leader, was shot to death in February 2004.
A leading Khmer Rouge tribunal monitor said Monday he was optimistic about the UN-backed court.
Suu Kyi was released on Saturday, imprisoned or under house arrest for most of the last 20 years.
Meanwhile, the tribunal continues to face funding woes, as donors wait for a completion strategy before deciding on the amount of funds.
Some were upset by the lack of provisions within Asean and its commission on key rights freedoms.
Activists say a general atmosphere of impunity still prevail, while police continue to seek bribes or commit abuses.
"Hello VOA" callers also expressed concern over torture in Cambodia, as well as land grabs and violence against human rights workers.
The ongoing dispute has led to a number of violent protests.
The rights group Licadho counted 118 instances of torture in detention in 2009 and another 101 cases in 2010.