Nuzman’s lawyer read out a statement at the BOC’s extraordinary general meeting in which the 75-year-old confirmed the news he himself had announced on Saturday.
He was arrested last Thursday in Rio de Janeiro as part of a probe into allegations he helped buy votes from the International Olympic Committee (IOC) to secure Rio’s hosting of the 2016 Games.
The IOC responded on Friday by suspending the BOC and stripping Nuzman of his honorary membership, while also removing him from the coordination committee for the 2020 Tokyo Games.
He has been held in prison ever since his arrest.
“Given the necessity to totally dedicate myself to my right to defend myself, I resign completely from my position as Brazilian Olympic Committee chairman and as honorary member of the general assembly,” Nuzman said in a letter read by his lawyer Sergio Mazzillo at the EGM, called last week after the IOC suspended the BOC.
Nuzman had already released a statement from prison on Saturday, but dated Friday, resigning from his position.
Brazilian officials said last month Nuzman was the “lynchpin” in a plot to bribe the IOC into awarding Rio the Games.
At the time, Nuzman was detained and questioned and authorities confiscated his passport.
Authorities allege that former Rio governor Sergio Cabral, who is serving a 14-year prison term for bribery and money laundering, masterminded the plot.
Investigators believe $2 million (1.7m euros) in bribes was paid to Papa Massata Diack, the son of Senegalese IOC member and former world athletics chief Lamine Diack, before the 2009 vote, won by Rio.
Businessman Arturo Soares, nicknamed “King Arthur”, a top contractor for Cabral’s administration, allegedly delivered the payment three days before the vote.
Rio beat bids from Chicago, Madrid and Tokyo to host the 2016 Games.