The United Nations human rights investigator for North Korea has called on Russia to renounce a new extradition treaty, voicing fears North Koreans seeking asylum could be forced back home and face punishment in violation of international law.

Key points: 10,000 North Korean labourers in Russia, some stay beyond their contract, UN says

10,000 North Korean labourers in Russia, some stay beyond their contract, UN says UN fears pact could be used to "repatriate workers"

UN fears pact could be used to "repatriate workers" Repatriated workers often tortured, abused, 2014 UN investigation says

Repatriated workers often tortured, abused, 2014 UN investigation says North Korea continues to reject investigation findings

An estimated 10,000 North Koreans are regular labourers in Russia, and some stay after their contracts have expired to seek asylum, said Marzuki Darusman, UN special rapporteur on human rights in the Democratic People's Republic of Korea (DPRK).

The extradition treaty, signed in Moscow on February 2, called for transferring and readmitting people who have "illegally" left their country or are staying "illegally" abroad, he said.

"Given the practice of the DPRK to send labourers to Russia, who often work in slave-like conditions, it is feared that such a treaty could also be used to capture and repatriate workers who attempt to seek asylum," Mr Darusman said in a statement.

Citizens forcibly repatriated to North Korea are often subjected to torture, arbitrary detention, summary executions, forced abortions and other sexual violence, he said, citing the findings of a landmark UN investigation in 2014.

North Korea stands accused by UN investigators, including Mr Darusman, of committing alleged crimes against humanity, marked by a system of Nazi-style atrocities including labour camps.

Mr Darusman, in his latest report this month, asked the United Nations to officially notify North Korean leader Kim Jong Un that he may be investigated for crimes against humanity.

North Korea continues to refuse responsibility for atrocities

Pyongyang has consistently brushed off the allegations and rejected any responsibility for human rights violations.

North Korean Foreign Minister Ri Su Yong is due to address the UN Human Rights Council on March 1.

The 47-member forum, which opens a month-long session on Monday, is to hold a debate on North Korea and Mr Darusman's report on March 14.

Japan and the European Union are drafting a resolution that would keep the spotlight on North Korea's record and renew the special rapporteur's mandate, diplomats said.

Mr Darusman, referring to North Korea's January 6 nuclear test and rocket launch, said: "The signing of the treaty took place against the context where the DPRK continues to commit deliberate belligerent acts, such as nuclear testing, followed by the latest missile launch."

"Such acts adversely impact on the constructive efforts to address the ongoing gross human rights violations in the country and reinforce even further the international community's resolve to pursue political and legal accountability."

Reuters