In January, Myanmar reached an agreement with Bangladesh on the repatriation of Rohingya refugees. In May, it struck an agreement with the United Nations that it presented as a first step toward their repatriation. But not a single Rohingya Muslim has been able to return as part of an official repatriation program, and United Nations agencies, which are still denied free access to Rakhine State, say there is no immediate prospect of starting one.

Moreover, the authorities had arrested most, if not all, of those who had made their own way back. They included 58 Rohingyas who returned between January and April and were then imprisoned. After receiving a presidential pardon, the members of the group were transferred to a “reception center” in conditions that Mr. al-Hussein likened to administrative detention. About 90 others who tried to leave Rakhine State by boat last month, but were forced back by engine failure, had also been detained.

Myanmar’s sincerity on repatriation would not be demonstrated by the number of agreements it signed, Mr. al-Hussein observed, but only by granting citizenship to the Rohingya, including 120,000 villagers displaced by violent clashes in 2012 and held in camps ever since.

He gave an equally stark assessment of prospects for any meaningful investigation by an independent commission of inquiry, which the government announced in May when it said it would look into allegations of violations by the security forces. The government has conducted a series of inquiries into these events but has issued blanket denials of abuses and has blamed Rohingya militants for instigating any violence.

The only exception, Mr. al-Hussein said, was a village massacre reported by Reuters that resulted in 10-year prison sentences for seven soldiers. Two Reuters journalists, Wa Lone and Kyaw Soe Oo, who investigated those events remain in jail on charges of violating Myanmar’s official secrets act.

“Myanmar has a pattern of investigative whitewashing,” Mr. al-Hussein told the Human Rights Council. “There is every reason to believe that another internal inquiry will again seek to whitewash the terrible crimes which have occurred, laying the ground for a new wave of violence in the future.”

Instead, he urged the council to create an independent international team that would use evidence gathered by a United Nations fact-finding team to investigate the criminal liability of individuals involved in the security forces’ campaign.

“Myanmar must grasp that the international community will not forget the outrages committed against the Rohingya,” he said, “nor will it absolve the politicians who seek to cover them up.”