Artur Taymazov, who competed for Uzbekistan throughout his Olympic career, was disqualified for his win in the 120-kilogram category at the London 2012 Games after testing positive for the banned oral steroid turinabol under a doping re-test program, the International Olympic Committee (IOC) said in a statement.
"The fight against doping is a top priority for the IOC, which has established a zero-tolerance policy to combat cheating and to make anyone responsible for using or providing doping products accountable," the IOC said, adding that the committee has been storing samples since the Athens 2004 Games.
The 40-year-old had already lost his Beijing 2008 gold medal in 2016 for doping.
He captured his first honor, a silver medal, at the Sydney Games in 2000 before going on to win the gold at the Athens 2004 Games, where he became the first Uzbek athlete to win a second medal.
The Russian-born Taymazov retired after defending his title at the London Games. In 2016, he became a politician in the State Duma, the lower house of Russia's federal assembly. He is also a deputy chair of its sports, fitness, tourism and youth committee.
The IOC has so far disqualified 24 medalists, including eight gold medal winners, from London 2012 during the reanalysis program, Sky News reported. A total of 60 athletes have been disqualified.
The committee said the program will continue through 2019 until the statute of limitations is reached the following year.
The Associated Press contributed to this report.