Myanmar State Counselor Aung San Suu Kyi reportedly avoided the issue of raping Rohingya women and girls by Myanmar troops and police when she met with a senior UN official recently, reports The Guardian.

Pramila Patten, the special envoy on sexual violence in conflict, went to Myanmar on a four-day visit in mid-December to place the issue before the government officials but was unable to have "any substantive discussion'' with Aung San Suu Kyi.

"The meeting with the state counselor was a cordial courtesy call of approximately 45 minutes that was, unfortunately, not substantive in nature," she wrote in a letter sent to UN secretary-general Antonio Guterres last week, The Guardian reports.

More than 655,000 Rohingya, members of a persecuted and stateless Muslim minority, have fled to Bangladeshi refugee camps since violence began in Myanmar's northern Rakhine state in August. Médecins Sans Frontières believes at least 6,700 Rohingya were killed during "clearance operations" ostensibly targeting militants, while many survivors say women and girls were gang-raped, reports the UK daily.

Instead of discussing the claims directly, Patten said Aung San Suu Kyi informed her she would enjoy "a number of good meetings" with senior Myanmar officials.

During these meetings, she was told by representatives of the military and civilian government that reports of atrocities were "exaggerated and fabricated by the international community".

"Moreover, a belief was expressed that those who fled did so due to an affiliation with terrorist groups, and did so to evade law enforcement," she wrote.

Myanmar's army has cleared itself of any wrongdoing in an internal investigation dubbed a "whitewash" by human rights groups.

While in the country, Patten met the man who headed that investigation, Lt-Gen Aye Win, who explained their methodology.

"The military investigation, which consisted of armed men in uniform 'interrogating' civilians in large group settings, often on camera, and then presenting rations to communities following their testimony and cooperation, clearly occurred under coercive circumstances, where the incentive structure was not to lodge complaints," Patten wrote.

"Accordingly, over 800 interviews yielded zero reports of sexual or other violence against civilians by the armed and security forces," she said.

Patten also expressed concerns about plans to send Rohingya who have fled back to Myanmar, citing the "prevailing climate of impunity" in the country.

Bangladesh and Myanmar have agreed to the "speedy" repatriation of Rohingya, scheduled to start by the end of January.

But many Rohingya say they will not return voluntarily until they are given citizenship as well as guarantees that they will be safe and not put into internment camps. Tens of thousands have been living in such camps elsewhere in Rakhine state since violence in 2012.

Skye Wheeler, the researcher for Human Rights Watch who investigated the sexual violence allegations, said Myanmar was denying a "terrible truth".

"The lack of acknowledgement or care the Myanmar authorities including Aung San Suu Kyi have shown for Rohingya women and girls who have been brutally raped by Myanmar soldiers as part of their ethnic cleansing campaign is almost as shocking as the horrific crimes themselves," she told the Guardian.

"It's like a second attack, to endure a vicious gang rape and then to be ignored, as if you don't matter at all, to have that terrible truth denied."

The Myanmar government was contacted for comment.