Russian investigators on Tuesday searched the offices of the country's largest social network VKontakte, an Investigative Committee spokesman told AFP.
"Yes, there is a search" at VKontakte's headquarters in central Saint Petersburg, Sergei Kapitonov, a spokesman for the committee's office in the northwestern city told AFP.
The social network VKontakte (vk.com) says on its website it has 200 million registered users, making it the most popular social network in the country.
"We are working... and suddenly twenty silent men in leather jackets appear," the company's technical director Nikolai Durov, who co-founded the company with his brother Pavel, wrote on his own VKontakte page.
"Turns out, it's a search... I wonder what they are looking for? Or perhaps they are gathering information and planting bugs?" he wrote.
Saint Petersburg police told Russian agencies the search was part of a probe into a recent accident near the company's office.
On Wednesday, investigators launched a probe into the April 5 accident, in which the driver of a white Mercedes ran over a traffic policeman and fled the scene.
Multiple reports then alleged that Pavel Durov was behind the wheel, which VKontakte denied.