Commission: NSA may have evidence about mysterious 1961 death of UN chief Dag Hammarskjold

A commission set up to recommend whether to reopen the investigation into the 1961 death of United Nations Secretary-General Dag Hammarskjold says America's National Security Agency may hold crucial evidence about how he died.

Hammarskjold's death is one of the great unsolved mysteries of the Cold War. Widely considered the U.N.'s most effective chief, Hammarskjold's plane crashed as he was attempting to broker a cease-fire deal between U.N. troops and rebel forces who were threatening to tear the newly independent Congo apart.

The Congo conflict was at the heart of interlocking international rivalries and conspiracy theories have been built around the crash ever since.

On Monday a commission of jurists recommended the U.N. reopen its investigation, adding that the NSA may be sitting on key evidence in the case.