Russian opposition leader Alexei Navalny accused President Vladimir Putin of using fraudulently obtains funds to build an ultra-opulent billion-dollar palace.

Navalny brought to light his accusation through a video that has now become viral on social media.

Navalny released the video on Wednesday and as of Thursday; the video had already gained more than 35 million views. In the video, Navalny said that Putin used his power and influence to obtain the funds to build the $1.35 billion Black Sea Palace.

Navalny claimed in the video that the palace was outfitted with high-end entertainment facilities, including an underground skating rink and a casino.

"It has impregnable fences, its own port, its own security, a church, its own permit system, a no-fly zone, and even its own border checkpoint," Navalny said.

Navalny said that the funds were gained from contributions made by Putin's allies, including oil chiefs and billionaires from around the world. Navalny, who just recovered after being poisoned by a military-grade nerve agent, said that the palace was built "with the largest bribe in history."

Putin spokesperson Dmitry Peskov shrugged off Navalny's accusations. Peskov said that Putin does not own the palace.

"These are all absolutely unfounded claims. This is pure nonsense," Peskov said.

The video was published just a few days after Navalny was arrested upon his arrival in Moscow from Germany, where he was staying to recover from being poisoned. The arrest was ordered by Moscow's prison service, which said that Navalny's detention was due to him violating his suspended prison sentence.   

The attempt on his life was allegedly done by a team working for the Russian Federal Security Service. Navalny fell into a coma while on a flight to Siberia. He was later transferred to a hospital in Siberia and then to another hospital in Berlin.

Tests conducted by the Organization for the Prohibition of Chemical Weapons, along with other independent labs, found that Navalny was poisoned using a Soviet-era nerve agent called Novichok.