The ministry of defence in Colombo said that a decision has been made to release information on the detainees, saying the details will be revealed only to the close relatives.
The move is being seen as a response to the nation's reconciliation commission report.
"A round the clock mechanism has been established by the terrorist investigation division to provide details of the
detainees and those who are already released", an official statement said.
Release of information of those detained by the forces since the end of the war with the LTTE was a major cause of concern for the Tamil minority parties.
Tamil parties claimed that those who surrendered at the end of the military conflict had disappeared without any trace.
The Lessons Learnt and Reconciliation Commission in its report made a number of important recommendation on the detainees.
The report noted several instances of LTTE detainees remaining in detention without charges and in which next of kin were not notified.
It also asserted that no person should be detained outside authorised places of detention.
The LLRC also had recommended the appointment of an advisory panel to monitor and examine detention.
The move comes ahead of Peiris' meeting with US Secretary of State Hillary Clinton in Washington on May 18.
The US had earlier urged the Lankan government to come up with an action plan on the LLRC recommendations, after it successfully adopted a resolution against Sri Lanka at the UN human rights council in March.
The resolution binds Colombo towards expeditious implementation of LLRC recommendations.
MPs' visit to Sri Lanka set to be a damp squib
Indian MPs send strong message to Lankan President
SL pull out of hosting Pakistan-Australia series
US lawmakers seek FTO tag for Haqqani network
The sour notes in Hillary's South Asia trip