Court official Yuko Maeda said the case against Ieng Thirith, charged with crimes against humanity and genocide, was stayed indefinitely and judges didn't impose many conditions on her release, the Phnom Penh Post reported Thursday.
"She will have to abide by Rule 35 [concerning not interfering with the administration of justice]," Maeda said. "The] judges will continue to undertake [an] inquiry into any medical developments that may help her condition."
Two weeks ago, a court-appointed panel of experts determined the 80-year-old former Khmer Rouge minister for social affairs suffered from moderate-to-severe dementia and wasn't fit for trial, the Post said.
Despite contradictory medical findings from her primary doctor, judges Thursday ruled there is "no prospect that the accused can be tried in the foreseeable future."
"Coercive conditions would in any case be difficult to enforce, given the accused's mental capacity," the judges said in a statement.
Prosecutors have 24 hours to appeal the decision by the U.N.-backed war crimes tribunal. If there is no appeal, she would be released Friday, the Post said.
Several million people are believed to have starved to death or been killed in what became known as the Killing Fields.