Russian oligarch Arkady Rotenberg says he is the owner of an opulent Black Sea mansion, not President Vladimir Putin, as the leaders’ critics had alleged.

A video report about the vast palace, by Kremlin critic Alexei Navalny, went viral across Russia and has now been watched more than 100m times.

The Russian president rubbished reports he owned the resort earlier this week.

Mr Rotenberg, a billionaire with close links to Mr Putin, went public claiming to be the owner on Saturday.

The revelation came in an interview posted on the pro-Kremlin Mash Telegram channel, before being confirmed to the Interfax news agency.

“I have managed to strike a deal with creditors a few years ago, and I became a beneficiary of this site a few years ago,” Mr Rotenberg’s press office quoted him as saying.

Mr Rotenberg said the property will be completed “in a couple of years” and is expected to become an apartment hotel.

The claim comes as a crackdown against opposition figures intensifies across Russia.

Controversy over the property has been rife following the publication of the documentary by jailed Kremlin critic Alexei Navalny’s team earlier this month.

Their investigation alleged the property cost £1bn ($1.37bn) and was paid for “with the largest bribe in history”.

The BBC’s Tim Whewell previously reported on the mysterious palace back in 2012, quoting a former business associate of Mr Putin who alleged that the mansion was built to his specifications for his personal use – but a spokesman dismissed the allegations at the time.

Earlier this week, the Russian president directly denied that he or his family owned it and described the video about it as “boring”.

The allegations about the palace have taken off on Russian social media, including video platform TikTok. The corruption allegations helped spur on protests held throughout the country last weekend in support of Mr Navalny – the biggest seen against President Putin in years.

More than 4,000 people were arrested as large crowds took to cities across Russia demanding Mr Navalny’s release.

The anti-corruption campaigner was immediately taken into custody after returning to Russia on a flight from Germany, where he had been recovering from an attempt to kill him with a nerve agent last year.

Both the heavy-handed police response and the continued detention of Mr Nalavany has drawn sharp international criticism.

Despite this, a crackdown seems to be intensifying.

A number of close associates of Mr Nalavany have been detained since last week and others, including his brother and Pussy Riot activist Maria Alyokhina, have been put under house arrest.

The chief editor of a Russian website specialising in human rights, Sergei Smirnov, was also arrested outside his home on Saturday. News of his detention, apparently over allegations he participated in last week’s protests, has been condemned by other journalists.

Further demonstrations are expected on Sunday, despite fresh police warnings about gatherings.

Officials have said that public transport routes and pedestrian movement will be limited across Moscow to try to curb protests.

Mr Rotenberg is a significant figure in Russia as the owner of huge construction firms which build infrastructure like bridges and gas pipelines. He is known to be close to Mr Putin as a former childhood friend and judo partner.

Mr Rotenberg and his brother were implicated during the FinCEN file revelations late last year.

The businessman has been under US sanctions since 2014, when officials described him as a member of the “Russian leadership’s inner circle” who they claimed provided “support for Putin’s pet projects”.