Alexei Navalny
Alexei Navalny posted a selfie on the way to the Moscow protest where he was arrested twitter

Kremlin critic Alexei Navalny has been arrested after taking to the streets of Moscow to join thousands of Russians protesting his three-and-a-half year suspended prison sentence for fraud.

Sentenced earlier on Tuesday [30 December] and still under house arrest, Navalny openly defied the measure by posting a selfie on the Moscow metro, apparently en route to Manezh Square where a huge throng of his supporters had arrived for a rally.

Protesters shouted "free Navalny" and "free Russia" during the demonstration, which began at 7pm local time.

A picture of the activist's arrest was published on social media soon after he was apprehended.

Navalny also sent his own tweet, preaching defiance in the wake of his detention.

The tweet reads: "The fact that I had been detained does not mean anything at all. I do not know how to do anything that you do not know how to do."

Navalny and his brother, Oleg, were both jailed for three and a half years for defrauding two firms of 30m rubles.

Navalny has maintained his innocence of all charges and said they were fabricated and politically motivated.