Alexei Navalny has reportedly been arrested once again, after he urged people to join an anti-corruption protest.
Navalny was on the way to a demonstration when he was detained at his home, according to his wife.
"Alexei has been arrested in the entrance to our block of flats," Yuliya Navalnaya wrote on Twitter. However she added, defiantly, "our plans haven't changed".
The lawyer and political activist had earlier urged his supporters to join demonstations planned across the country for Monday June 12, which is also a national holiday in Russia. He had also demanded that Russia's Prime Minister Dmitry Medvedev tender his resignation.
Navalny has been trying to sway public opinion to garner support for a candidacy in order to oppose Vladimir Putin in next year's election. In March, he played a central role as thousands of people turned out for demonstrations against the government.
However Navalny himself has been repeatedly arrested over the years - most recently in March, when he was imprisoned for 15 days.