A Moscow court has put Russian opposition leader Alexei Navalny under house arrest, forbidding him from using the Internet or communicating with anyone outside his family.
The house arrest is for two months but can be extended.
Navalny was sentenced to seven days in prison on Monday for participating in an anti-government protest and was taken to court on Friday from the detention centre.
He is a leading opposition figure and anti-corruption crusader. Navalny and his supporters published a damning report in January, documenting corruption in the preparations for the Sochi Olympics.
His spokeswoman Anna Veduta said in a Twitter post that Navalny is barred from writing, texting, posting messages on social networks or using the Internet. He is allowed to communicate only with his family. He can receive visitors, Veduta said, but not speak to them.
In July last year, Navalny was found guilty of fraud and sentenced to five years in prison. A day later, however, he was released on a suspended sentence following mass street protests in Moscow.
Navalny spearheaded massive anti-government protests in 2011 and 2012 and finished second in last year's Moscow mayoral race with a third of the vote. The campaigner has faced numerous probes, which he attributes to his investigations shedding light on wide-spread corruption in the Russian ruling elite.