Putin and his allies love buying art. To help us win the war in Ukraine, confiscate it | Vladyslav Vlasiuk

Paintings and sculptures are easier to transport and hide than yachts and private jets. Don't let them slip through the net

Rene Magritte, one of Belgium's most famous artists, was a leading member of the 1920s movement called surrealism, which sought revolution against the constraints of the rational mind. When describing his paintings, Magritte said they evoke mystery" and strived to ask beholders: What does that mean? It does not mean anything, because mystery means nothing, it is unknowable." I sometimes feel as if I am looking at a Magritte painting when examining Russians' ability to evade western sanctions policies.

Arkady Rotenberg, worth a reported $3.5bn (2.9bn), is a childhood friend of Vladimir Putin. He used to be the Russian president's judo sparring partner, before progressing to become a rich businessman. Rotenberg has publicly claimed to own the $1bn so-called Putin's Palace", a huge Italianate complex on the Black Sea coast said to be secretly owned by the Russian president.