Navalny aides says he has disappeared within Russia's prison system

Russian opposition politician Alexei Navalny has been removed from the penal colony where he had been imprisoned since the middle of last year and his current whereabouts are not known, his allies said on Monday.

Navalny aides have been preparing for his expected transfer to a "special regime" colony, the harshest grade in Russia's prison system, after he was sentenced in August to an additional 19 years in prison on top of 11-1/2 years he was already serving.

Navalny's spokeswoman Kira Yarmysh said staff at the IK-6 facility in Melekhovo, 235 km (145 miles) east of Moscow, had told his lawyer waiting outside that the opposition leader was no longer among its inmates.

"Where they have taken him, they refuse to say," she said on social media platform X.

His disappearance comes at the start of the campaign period for a presidential election in which Vladimir Putin confirmed on Friday that he would stand for another six-year term.