Britain's UN envoy on Tuesday suggested the UN Security Council could consider helping Myanmar collect evidence of crimes committed during a military crackdown of the Rohingya people, denounced by the world body as ethnic cleansing after most recent bout of persecution of the Muslim minority last year.

Read More: Myanmar urged to hold 'proper' probe into alleged atrocities against the Rohingya

"What we've got to do on the council is to think how best to turn that into something operational, so that the evidence gets collected and given either to the Burmese authorities or to some sort of international mechanism," Britain's UN Ambassador Karen Pierce told Reuters, as the Security Council wrapped up a four-day visit to Bangladesh and Myanmar on Tuesday.

Britain's Pierce told reporters that an investigation needs evidentiary standards to achieve accountability.

"There are two ways of doing that basically, one is an International Criminal Court referral, the second would be the Burmese government do that themselves," Pierce said.

The Myanmar mission to the United Nations did not immediately respond to a request for comment on Pierce's suggestion.

Myanmar's de facto leader Aung San Suu Kyi pledged investigations if credible evidence was provided and military chief Min Aung Hlaing vowed "harsh action" over sexual violence during separate meetings with Security Council envoys in the country's capital Naypyitaw on Monday, diplomats said.

But Suu Kyi's civilian government has little control over the Myanmar military.

Members of the UN Security Council travelled to Myanmar's Rakhine state, where the United Nations and rights groups say nearly 700,000 Rohingya have fled to Bangladesh since August.

Fleeing refugees have reported killings, rapes and arson. Rohingya insurgent attacks on Rakhine security posts led to the military operation that Myanmar deemed a legitimate response.

In Rakhine, data from the U.N. Operational Satellite Applications Programme (UNOSAT) has shown hundreds of villages once inhabited by the Rohingya have now been burned down. Many such villages could be seen from the Myanmar military helicopters that carried the UN envoys to northern Rakhine.

Security Council envoys were shown a reception centre Myanmar has built for repatriating Rohingya, aiming to accept a total of 150 people a day, and a transit camp that can house 30,000 returnees. The envoys passed two bulldozed villages near the camp.

INVESTIGATIONS AND OPTIONS

Last November, the Myanmar's military released a report denying all accusations of rape and killings by security forces.

But the US government is conducting an intensive examination of allegations of atrocities against the Rohingya that could be used to prosecute Myanmar's military officials for crimes against humanity, US officials have told Reuters.

Meanwhile the prosecutor of the International Criminal Court (ICC) has asked it to rule on whether it has jurisdiction over the deportations of Rohingyas to Bangladesh, a possible crime against humanity, but Suu Kyi's government has expressed "serious concern" over the move.

Bangladesh is a member of the ICC but Myanmar is not, so if the ICC rules that it does not have jurisdiction, the UN Security Council could then choose to refer the situation in Myanmar to the court.

In December, US Ambassador to the United Nations Nikki Haley said Myanmar must allow an "independent, transparent and credible investigation into what has happened."

One way the Security Council could help Myanmar could be to mandate a UN investigative team to collect, preserve and store evidence, just as it did in Iraq last year when it investigated acts by Islamic State that may be war crimes.

The United Nations General Assembly could alternatively create an international inquiry into the most serious crimes committed against the Rohingya, similar to what the UN has done in Syria.

Russia's deputy UN Ambassador Dmitry Polyanskiy was wary of Security Council involvement though because Myanmar said it was willing to tackle the issue. Any Council resolution would need nine votes in favor and no vetoes by either Russia or China, an ally of Myanmar.