Mamatov earned Winter Olympic golds in the 4x7.5 kilometres relay at both Grenoble 1968 and Sapporo 1972.

He was also a four-time world champion - in the 20km individual race in 1967 and in the 4x7.5km relay from 1969 to 1971.

Mamatov also coached the Soviet Union team at the Sarajevo 1984 Winter Olympics and headed the sports delegation of the national team at the 1988, 1992, 1998 and 2002 Winter Olympics.

He was President of the USSR Biathlon Federation from 1989 to 1992 and vice-president of the International Biathlon Union from 1993 to 2002.

IBU President Olle Dahlin told Russia's official state news agency TASS: "The IBU is very saddened by the news that the organisation’s former vice-president Viktor Mamatov has passed away.

"Viktor was extremely passionate about biathlon and made a significant contribution to the sport during his brilliant career as an athlete, coach, and IBU vice-president, and with the Russian Biathlon Union and the Russian Olympic Committee.

"A two-time Olympic champion and four-time world champion, he later became a successful coach of the USSR national team, and made an important contribution to the founding and successful development of the IBU.

"Victor enjoyed universal respect and sympathy in the biathlon family.

"Our thoughts are with his family and friends at this difficult time."

Anna Bogaliy, who won Olympic 4x6km relay golds at the 2006 and 2010 Winter Olympics, told TASS she last saw Viktor Mamatov on October 18, and that he had been talking about writing his life story.

"It seems he never had time to finish the book; even at the anniversary he said that he was working on it," Bogaliy said.

"The last time I saw him was on October 18, we went to see him with [the President of the Russian Biathlon Union] Viktor Maigurov, and with Elena Sedykh from the Russian Olympic Committee.

"We weren't there for long - it was already hard for him, we talked for about 15 minutes. The handshake was strong. But he was already giving in.

"We left him with a conflicting state - it was as if we were saying goodbye…

"But it’s good that they managed to rename his school during his lifetime, his centre in Novosibirsk, which he built.

"He also built the Olympic Reserve School in Novosibirsk.

"Wherever he worked - everything was for the benefit of people, for the benefit of sports, for the good biathlon, true values.

"He always helped and mentored everyone."

Oleg Matytsin, Russian Minister of Sports, added: "Today, the outstanding biathlete, two-time Olympic champion Viktor Fedorovich Mamatov passed away.

"It is bitter to realise that our teachers are leaving, those who have always been an example of honesty, sincerity and hard work.

"After the end of his sports career, Viktor Fedorovich was engaged in teaching, he popularised biathlon, worked for the benefit of domestic sports.

"His departure is a great loss for the entire sports community."

The Honorary President of the Russian Olympic Committee (ROC), Vitaly Smirnov added: "He was a great athlete, a champion.

"Fate brought us together in a very difficult time - in the 1990s, during the collapse of the Soviet Union.

"He worked as deputy chairman of the USSR Sports Committee for winter sports, vice-president of the ROC.

"He was a wonderful, responsible person.

"He cared about the business and did a lot to preserve not only skiing, but also all winter sports."