Drnovsek

The FBI also spied on meetings that Mandela had with foreign leaders in the early 1990s, including a meeting in Namibia with Janez Drnovsek, then president of Yugoslavia, who was also leader of the Non-Aligned Countries group that did not support the U.S. or Soviet Union during the Cold War.

They include a record kept by federal agents of a meeting in Namibia just a month after Mandela’s release from jail between him and the then president of Yugoslavia, Janez Drnovsek.

Drnovsek Zorko, who earlier this month was on the winning University Challenge team, says his friends sometimes produce one for him at social gatherings.

Filip Drnovsek Zorko, a Slovenian studying at Cambridge University, has 12 cubes in his room.

Earlier this month, Slovenia's ambassador to Japan, Helena Drnovsek Zorko, apologised for her "carelessness" in signing the treaty on behalf of her country.