Bruno Pontecorvo (, Bruno Maksimovich Pontekorvo; 22 August 1913 – 24 September 1993) was an Italian nuclear physicist, an early assistant of Enrico Fermi and then the author of numerous studies in high energy physics, especially on neutrinos. According to Oleg Gordievsky (the highest-ranking KGB officer ever to defect) and Pavel Sudoplatov (former deputy director of Foreign Intelligence for the Soviet Union), Pontecorvo was also a Soviet agent. A convinced communist, he defected to the Soviet Union in 1950, where he continued his research on the decay of the muon and on neutrinos. The prestigious Pontecorvo Prize was instituted in his memory in 1995.