The Russian businessman Arkady Rotenberg said on Saturday he owns a palace in southern Russia which jailed Kremlin critic Alexei Navalny has linked to Vladimir Putin. Navalny and his anti-corruption foundation have published a video in which they allege the opulent mansion belongs to the Russian president. The video has been viewed more than 103m times. Rotenberg, Putin’s former judo sparring partner who sold his stake in the gas pipeline construction firm Stroygazmontazh in 2019 for a sum which RBC business daily puts at some 75bn roubles (£72m), said he bought the palace two years ago. “Now it will no longer be a secret, I am the beneficiary,” Rotenberg said in a video published by Mash channel in Telegram. “There was a rather complicated facility, there were a lot of creditors, and I managed to become the beneficiary.” He gave no further financial details of the purchase or how it had been funded. Putin has denied ownership of the palace. Navalny was remanded in custody for 30 days on 18 January for parole violations he says were trumped up. He could face years in jail. He was arrested after flying back to Moscow from Germany, where he had been recovering from a nerve agent poisoning last August. After Navalny’s arrest thousands of people joined unsanctioned protests across Russia last Saturday to demand the Kremlin release him from jail. His supporters plan to hold further protests across Russia on Sunday. Authorities have declared the rallies illegal and vowed to break them up. Rotenberg was among the Russian officials and business executives blacklisted by the US and other western states in the aftermath of Russia’s annexation of Crimea in March 2014. Russian police on Saturday detained Sergey Smirnov, editor-in-chief of independent media outlet Mediazona, in Moscow on suspicion of taking part in last weekend’s Moscow protest, Mediazona said on Saturday.