Respectfully, this is like me asking about Obama and you replying with a Dinesh D'Souza hitjob. That video has been thoroughly debunked as a baseless conspiracy theory.
Arkady Rotenberg and others have claimed current or prior ownership of the property. It really is just a conspiracy theory produced by rabidly anti-Putin media operatives like Navalny -- the exact same playbook as Dinesh D'Souza or "Project Veritas".
The original allegation was made by Sergei Kolesnikov, not Navalny. Reuters traced the money which was used to build Putin's Palace. Any of Putin's associates can claim ownership in order to take the heat off of him, but it is his to use as he sees fit.
