Secretary-General Antonio Guterres has appointed Tanzania's former chief justice to review potential new information, including from South Africa, on the mysterious 1961 plane crash that killed U.N. Secretary-General Dag Hammarskjold.

U.N. deputy spokesman Farhan Haq said Friday that Mohamed Chande Othman, who recently retired as Tanzania's top judge, would lead the review which former U.N. secretary-general Ban Ki-moon called for in August and the General Assembly requested in a resolution adopted on Dec. 23.

Hammarskjold was on a peace mission to newly independent Congo when his plane crashed in what is now Zambia.

The resolution asked the U.N. chief to appoint "an eminent person" to review and assess the value of any potential new information "to determine the scope that any further inquiry or investigation should take and, if possible, to draw conclusions from the investigations already conducted."

An independent panel reviewing new information about the crash said in July 2015 that the United States and Britain retained some classified files, and that South Africa had not responded to several requests for information.

The panel's 99-page report put to rest claims that Hammarskjold was assassinated after surviving the crash. But it has long been rumored that his DC-6 plane was shot down, and the panel provided new information about a possible aerial attack or interference.

Ban said in a note last August that Britain again refused to release classified material in response to U.N. requests for information. He said responses from the United States and Belgium didn't alter the panel's conclusion that the possibility of an aerial attack or interference should be pursued.

Ban's note included a letter dated July 1, 2016 from South Africa's U.N. Mission saying the government fully supports the U.N. investigation and "the Department of Justice and Constitutional Development has directed that a search be undertaken for any documents, records or information."

The panel had cited documents from the South African Institute for Maritime Research that refer to "Operation Celeste," purportedly to "remove" Hammarskjold with cooperation from then U.S. CIA director Allen Dulles. It was not able to conclude whether the documents were authentic.

Ban said the United Nations also received additional information about Hammarskjold's death after the panel's report.