A genocide is still underway against Myanmar's Rohingya Muslims, a UN fact-finding team said Wednesday as it presented a report at the Security Council calling for the matter to be referred to the International Criminal Court.

Marzuki Darusman, chair of the UN Fact-Finding Mission on Myanmar, told a press conference that beyond mass killings, the conflict included the ostracization of the targeted population, prevention of births, and widespread displacement in camps.

"It is an ongoing genocide," said Darusman.

"We consider the genocide intent can be reasonably inferred," he added as he presented the team's report at a Security Council meeting called by Western powers but opposed by China and Russia.

The fact-finding mission's explosive 444-page report was first made public last month. It called on the council to refer the Myanmar situation to the International Criminal Court in The Hague, or to create an ad hoc international criminal tribunal, as was done with the former Yugoslavia.

The report said that Myanmar's top generals, including Commander-in-Chief Min Aung Hlaing, must be investigated and prosecuted for genocide in Rakhine State.

Myanmar has rejected accusations that its military committed atrocities in the crackdown last year that forced 720,000 Rohingya to flee over the border to Bangladesh.

The conflict has also seen some 390 villages destroyed and 10,000 Rohingya killed, said Darusman.

"The conditions are not in place for a safe, dignified and sustainable return of the Rohingyas in Bangladesh," to Myanmar, he warned, adding any attempt would just risk more deaths. 

He added Myanmar's internal inquiries have "proven to be ineffective failures" so far.

The UN's Special Envoy to Myanmar Christine Schraner Burgener added: "Accountability is one of two important pillars for national reconciliation, the other is inclusive dialogue.

"Credible fact-finding is the first step towards accountability."

The Myanmar government rejected the UN mission's findings, questioning its independence and pointing out that it had established itself an independent investigative commission made up of Asian diplomats.

Myanmar maintains that the violence in Rakhine was triggered by Rohingya extremists who attacked border posts in August 2017. (AFP)