The information comes from the Russian opposition politician Alexei Navalny and his organization, which also came across pictures, both of the palace's exterior and its interior.
This is mainly thanks to people who worked with the palace and were shocked by the extravagance, Navaljny's organization states.
The palace contains an Alexei Navalny, including a full-size hockey rink, an amphitheater and an underground tunnel directly to the sea.
Alexei Navalny claims that Putin has been able to hide many billions of rubles in order to build the palace through an advanced corruption plan for many years.