Anthony Nnamdi Okeakpu, 29, was arrested by British police on behalf of USA authorities for allegedly being a member of the Infraud Organisation, the country's Department for Justice said.
One advert posted on Infraud's online forum in 2011 claimed to have 795,000 log-ins for British customers of HSBC, the indictment says. Another eight have been detained in other countries including Australia, Italy, and Serbia, and await extradition to the US.
The indictment "marks a significant step in the battle against transnational cyber crime", Deputy Assistant Attorney General David Rybicki told reporters on a conference call Wednesday.
The US Justice department has filed an indictment in the US District Court against Australian Edgar "Guapo" Rojas and 35 others, describing it as one of its largest cyberfraud prosecutions.
Bondarenko remains at large, but the number two figure in the organisation, Russian co-founder Sergey Medvedev has been arrested, according to United States officials.
Along with Bondarenko, those arrested included a number of moderators for the forum, along with vendors and "VIP members", although the overall number arrested was only a small percentage of the forum's estimated 11,000-plus members. The group's activities resulted in approximately $2.2 billion in intended losses and more than $530 million in actual losses to banks, merchants and private citizens over Infraud's seven-year history, prosecutors said. Users could also use the site to advertise malware for sale.
Following the indictment by a USA grand jury alleging racketeering conspiracy and other crimes, federal, state, local, and global law enforcement authorities arrested 13 people from the U.S. and six other countries, including Australia, the United Kingdom, France, Italy, Kosovo and Serbia. The underground forum, accessible on the dark web, had 10,901 registered members as of March 2017. Members of the group were charged on nine criminal counts, including wire fraud, computer crimes, and conspiracy to racketeer.
"This case reflects the alarming and increasing threat posed by cyber crime".
Five of those suspects have been arrested in the US.
The City of London Police are credited alongside other worldwide police forces for "siginificant efforts and timely cooperation".