A Russian oligarch’s $600 million divorce battle involving artworks by Andy Warhol and Mark Rothko is heading to court in London this week.

Tatiana Akhmedova is accusing her ex-husband, oil magnate Farkhad Akhmedov, of transferring cash and assets to their son, Temur, a commodities trader, in order to keep them out of her hands. She has been working to get a hold of the assets since they were awarded to her in a legal decision in 2016.

A quarter of that amount comes from 11 works by artists including Warhol, Rothko, Yves Klein, Damien Hirst, and Peter Doig. The collection, which Akhmedova curated, according to a judge’s findings, has been valued at $145.2 million. Among the works are Rothko’s Untitled (Yellow and Blue) (1954), which previously sold at Sotheby’s in 2015 for $46.5 million, and Doig’s Country-rock (Wing-mirror) (1999), which fetched $14.5 million at Sotheby’s London in June 2014. The collection reportedly also includes several of Warhol’s depictions of Marilyn Monroe and one of Brigitte Bardot.

Authorities suspect that the collection is being hidden in Liechtenstein, where, in 2016, Akhmedov moved the collection to a vault called Stabiq Treasure House, according to court papers.

Other assets at issue include the 377-foot yacht Luna, which features a 66-foot swimming pool and a missile detection system; an Aston Martin; a $40 million London apartment gifted to Temur for his 19th birthday; a helicopter; a private jet, and some pricey shotguns. Akhmedova’s long legal battle has stretched from London to Lichtenstein to the Marshall Islands, where the Luna is registered, to San Jose, California, where a judge ordered Google to hand over her son’s emails.

In 2012, Akhmedov sold his stake in a gas company for $1.4 billion, according to the Daily Beast.

He has so far surrendered only $7 million to his ex-wife and what the Daily Mail calls “a rusty helicopter.”