Usmanov is thought to be worth some $15 billion — he holds assets in steel and mining and is a major stakeholder in the Arsenal football club, the Guardian adds.
In a statement, Usmanov says that "a situation in which an outstanding scientist has to sell a medal recognizing his achievements is unacceptable." He notes that Watson's work has contributed to cancer research, a disease that has affected his family.
"It is important for me that the money that I spent on this medal will go to supporting scientific research, and the medal will stay with the person who deserved it," he adds.
Watson, who won the Nobel Prize in 1962 with Francis Crick and Maurice Wilkins for determining the structure of DNA, had said he was selling the prize out of both financial necessity and to raise money for charity and research.