Amnesty International on Thursday called for Bangladesh's military-backed government to set up a "truth commission" to probe war crimes from the 1971 independence struggle against Pakistan.
The group's secretary general Irene Khan said the impunity with which law enforcers committed human rights abuses could be traced back to the war and the failure of subsequent governments to bring those responsible to justice.
Khan, a Bangladeshi, said she had raised the issue with the emergency government, which marks its first year in power on Friday.
"They all said that the establishment of a truth commission is important and necessary and indicated that they will be giving serious consideration to how they can do this," she said.
An unknown number of people died in the bloody nine-month independence war. Some Bangladeshis were accused of collaborating with the Pakistan army to carry out atrocities.
"This is a fresh call for justice... the best way to heal the wounds of this nation. This unelected government should have the courage to do what previous elected governments have failed to do," Khan said.
"This would be a symbol of the commitment by the government to the rule of law and an end to impunity," she added at the end of a week-long visit to Bangladesh.
She said human rights abuses including extra-judicial killings had been committed under all previous governments and acknowledged that, although abuses continued, there had been a reduction under the current regime.
"There is a culture of impunity and non-accountability that has persisted for decades and that must come to an end," she said.
The government has pledged to reinstate democracy later this year through elections after completing a major corruption crackdown.
It came to power after unrest over vote-rigging allegations led to elections scheduled for last January being cancelled.