Human rights groups are expressing skepticism over claims by Burma's new human rights commission that as few as 300 of the nation's suspected 2,000 political prisoners are still incarcerated.

A Thailand-based rights group told VOA's Burmese service it is aware of more than 1,600 political prisoners still in jail in Burma. Amnesty International researcher Benjamin Zawacki told VOA on Monday that Burmese authorities should release the names of the remaining prisoners so the list can be cross-checked against those still believed to be jailed.

In an open letter published in Burma's state-controlled press Sunday, the national human rights commission called for the release of all remaining political prisoners. But it said that when government ministries asked Western governments for a list of the 2,000 prisoners of conscience still believed to be in custody, they found only 500 of those were actually in prison.

The commission said about 200 of the 500 prisoners were included in a recent mass amnesty that saw more than 6,000 prisoners released.

The Assistance Association for Political Prisoners, which is based in Thailand, told VOA's Burmese service it has documented 1,667 political prisoners who remain imprisoned after the mass release. And the National League for Democracy, led by democracy activist Aung San Suu Kyi, said it is in contact with at least 500 remaining prisoners and cannot say how many more are still incarcerated.

Zawacki told VOA the Burmese rights commission's figures are close to those of the Burmese government, which has claimed previously it is holding only about 600 of what Western governments call prisoners of conscience. Officially, Burma maintains that all of its prisoners are jailed because they committed crimes.

The Amnesty official said some of the discrepancy can be explained by a disagreement over which prisoners are being held for political reasons and which ones have committed crimes.

He said Amnesty's position is that it is incumbent upon the Burmese authorities to disclose all the names in a transparent manner so that outside groups and governments can determine the truth.