RuLeaks.net says it has no proof the mansion, still under construction and being built for a reported $1 billion, is Putin's.
The mansion was first brought to public attention in December by a former business partner of Putin associates, who published an open letter to President Dmitry Medvedev decrying corruption in Russia.
Pirate Party leader Pavel Rassudov, who denies connections to RuLeaks.ru, nevertheless told RFE/RL's Russian Service that the number of visitors to the site have spiked since it was launched a month ago.
"We have to confirm the mansion [is Putin's]," he said. "Then there has to be action, an appeal to the president asking whether there's corruption involved."
-- Gregory Feifer