The United Nations Monday appointed a panel to reinvestigate the 1961 plane crash death of Secretary-General Dag Hammarskjöld. Current Secretary-General Ban Ki-moon said Mohamed Chande Othman, the chief justice of Tanzania, would head the independent panel of experts examining new information related to the plane crash.

Hammarskjöld, a Swedish diplomat, was 47 when his plane crashed en route to ceasefire talks to end the fighting between U.N. forces and Katangese troops led by Moise Tshombe in the former Belgian Congo. The plane went down in the British protectorate of Northern Rhodesia (now Zambia), killing Hammarskjöld and 15 others.

The investigating panel is scheduled to convene March 30 to "examine and assess the 'probative value' of new information related to the death of Mr. Hammarskjöld and the members of the party accompanying him on an aircraft that crashed in what is today Zambia on the night of 17-18 September 1961," the U.N. said in a statement. The panel is scheduled to present its findings by the end of June.

Questions have long swirled over whether Hammarskjöld's plane, a Douglas DC-6, was shot down. The four-engine plane crashed in the bush about eight miles from the airport in Ndola just minutes after its final radio contact, the New York Times reported. The three-member panel has the power to travel to the crash site and interview witnesses. Members also will have access to documents the U.N. has urged be disclosed.

Two U.S. intelligence workers who have said they heard evidence the plane was shot down are expected to testify, the Times said. The two were manning listening posts hundreds of miles apart in the Mediterranean.

Former President Harry Truman apparently believed Hammarskjöld had been assassinated. He was quoted as saying Hammarskjöld “was on the point of getting something done when they killed him. Notice that I said ‘when they killed him,’” according to a December story in the Guardian.