Anti-corruption campaigner and leading Russian opposition figure Alexei Navalny says he has been taken in for questioning, escorted by a dozen police who met him outside his Moscow apartment building.

Navalny, a vehement foe of President Vladimir Putin, was convicted in late December of fraud and given a 3 ½-year suspended sentence. The court said that until his appeals are exhausted he must remain under house arrest.

He has been allowed to leave his home in recent days, but has been followed by law enforcement officers posted outside his door.

Navalny posted on Twitter that he was met Friday morning by 12 police officers and taken to the federal Investigative Committee, which had summoned him for questioning about his anti-corruption activities.