Russian officials began the investigation of Igor A. Gusev Tuesday, The New York Times reported. Officials said Gusev likely fled the country.
With fewer financial incentives, spammers have cut their activity by an estimated 50 billion messages a day.
"We've seen a sustained drop in global volumes," Henry Stern, a senior security analyst at Cisco Systems told The New York Times. Cisco highlighted the closure of Mr. Gusev's site as the cause for this reduction.
Russian authorities accuse Gusev of operating a pharmacy without a license and failing to register his business. Computer-related charges may follow once police search the contents of computers found in Gusev's apartment.
Gusev's lawyer, Vadim A. Kolosov, told The New York Times that Gusev did not own SpamIt.com and never sent spam e-mail.