Sri Lankan President Mahinda Rajapaksa has appointed a three-member panel to probe the mass grave found in the central district of Matale, his office said on Friday.
Retired judges SI Imam, Bandula Atapattu and Dhammika Kitulegoda man the panel under Imam's chair.
They will commence their work within two days and are expected to make a report within a six month period, officials said.
A mass grave of over 150 skeletal remains was discovered in the central town of Matale in November last year.
This surfaced during the digging of the ground to build a new structure for the Matale hospital.
Marxist JVP or the Peoples Liberation Front claimed the victims were their members as a result of the government crackdown on a rebellion during 1987-90.
Forensic reports had confirmed that the grave could not be older than 1986 and not newer than 1990.
The crackdown on the JVP rebellion ended during the early part of 1990.
The JVP led a public outcry for an independent probe alleging that the main opposition UNP then in government was responsible for the murder of their cadres.
They accused the current government of trying to cover up as most of the UNP members then are now part of the ruling coalition.
President Mahinda Rajapaksa in April promised the appointment of the panel.