Fears over the fallout from a UN report detailing the human rights situation in Burma, and which is being delivered in March by rights’ envoy Tomas Ojea Quintana, may have spurred the government into promising the release of all “prisoners of conscience”.

Parliamentary speaker Shwe Mann is quoted by the domestic Weekly Eleven journal as acknowledging that the 13 January amnesty of political prisoners might not have been all-encompassing.

Shwe Mann, a powerful figure in the government and former third-in-command of the junta that ceded power in March last year, met with Quintana during his visit last week. The parliamentary speaker was reportedly pressed by the envoy to come clean on the remaining dissidents behind bars, to which he replied:

“We said that the latest prisoner release was based on the list of the NLD [National League for Democracy], and the remaining prisoners of conscience might be those who breached laws,” he said. The wording of the statement appears to be an admittance that highly arbitrary laws have been used to jail opposition figures, something long denied by a government known for criminalising freedom of speech and media.

“However, I promised him that more prisoners of conscience would be examined and released if the NLD provides a list of them,” he continued.

The categorisation of the thousands of opposition figures that were jailed in Burma during military rule has been a topic of hot debate: the government has long refused to acknowledge the presence of ‘political prisoners’, but has begrudgingly adopted the term ‘prisoners of conscience’ in recent months.

Like the NLD, however, it rejects the notion that detainees jailed for committing or intending to commit violent acts, such as rebel soldiers, can be classed ‘prisoners of conscience’.

However Shwe Mann appears to concede, perhaps inadvertently, that highly arbitrary laws, if any, were used to jail opposition figures

Prior to the January amnesty, the party produced a list of 591 political prisoners, only 299 of which were freed. Around 300 others released were former intelligence agents and customs officials purged after the fall of ex-prime minister Khin Nyunt, and whose jailing, despite being largely on charges of corruption, was likely politically motivated.

Quintana, who was able to visit the notorious Insein prison in Rangoon, said upon his departure on 5 January that despite a “wave of reforms” in recent months, “serious challenges remain”.

He is due to submit a report to the UN in March in which he will examine the continuing obstacles to democracy in a country where many top government ministers held senior ranks in the former junta.

The issue of the remaining political prisoners, among whom are nearly 50 monks, is seen as problematic for western countries increasingly keen to engage with the government – both the EU and US say their release must come before the dropping of sanctions.