The operation – which targeted a 25-room villa on the southern Italian island of Sardinia – is part of broader efforts aimed at penalising wealthy Russians linked to President Vladimir Putin after Moscow’s invasion of Ukraine in February.
It comes after Mazepin was fired in March by US-owned F1 team Haas in March.
Days later, he was named on an EU sanctions list along with his father, the owner and chief executive of chemical giant Uralchem.
The bloc’s official journal described Dmitry Mazepin as a member of Putin’s closest circle.
In recent weeks, Italian police have sequestered villas and yachts worth over €900 million from wealthy Russians who were placed on the sanctions list following the Ukraine conflict.
The most valuable asset seized so far is a superyacht owned by billionaire Andrey Igorevich Melnichenko, worth around €530 million, which was impounded in the northern port of Trieste.