Yves Bouvier pushes to have New York art consultant’s dealings revealed in US court

In a recent affidavit, Sandy Heller confirms he worked as an art adviser for Dmitry Rybolovlev and could still be questioned about his conversation over Modigliani purchase

The New York-based art consultant Sandy Heller has disclosed he was employed by Dmitry Rybolovlev, the Russian billionaire and owner of AS Monaco football club, as an art adviser in February 2015. Heller’s position was revealed in an affidavit he submitted to a US federal court in December following a petition filed by the Swiss freeport magnate, Yves Bouvier, to have Heller questioned about his dealings with the Russian collector. Bouvier is now pushing to have further documents connected to the sale of a painting by Modigliani disclosed.

The revelation is the latest twist in a long-running legal battle between Rybolovlev and Bouvier, which began in January 2015 when the family trusts controlled by the Russian oligarch filed a criminal complaint in Monaco, accusing Bouvier of complicity in money laundering and fraud.

The legal case was allegedly sparked when Heller told Rybolovlev during a chance meeting in December 2014 on St Barts Island that Heller’s client, the hedge-fund manager Steve Cohen, had sold Amedeo Modigliani’s Nu Couché au Coussin Bleu for $93.5m. Bouvier's company acquired the work and later arranged for Rybolovlev to buy the same painting for $118m.

Bouvier, who has firmly denied any wrongdoing, filed a petition in US federal court in September to have Heller questioned about his dealings with Rybolovlev and to secure related documents, including a copy of their financial arrangement.

The petition was largely denied in December, but the judge ordered that Bouvier’s lawyers should be provided with a copy of the February 2015 financial agreement between Rybolovlev and Heller, as well as any documents that relate to Heller’s involvement in the Modigliani sale.

Bouvier’s lawyers are now asking to see emails concerning two letters from Heller and Cohen that confirm the original price of the Modigliani, according to a filing on 9 March. A spokesman for Bouvier’s lawyers says he believes Heller will still be questioned about his conversation with Rybolovlev on St Barts.

Through Heller’s expertise, Rybolovlev estimated that Bouvier overcharged him around $1billion in the purchase of 38 works of art, according to a statement filed in the US court. Bouvier’s lawyers are now calling into question “Heller’s lack of independence in assessing those damages”, which are “impacted by Heller’s separate art advisory arrangement with Rybolovlev”. Neither Heller nor his lawyers could be reached for comment.

In his affidavit, Heller says he was retained by Rybolovlev as an art adviser and that the Russian billionaire’s lawyers are “relying on him as a consulting expert” for other legal cases. The US art consultant also says Bouvier’s petition sought “to obtain for his own purposes competitive confidential information and trade secrets relating to my business and Mr Rybolovlev’s art transactions”.

Meanwhile, other reports last week that US prosecutors had opened an inquiry into Bouvier were unconfirmed. “Yves Bouvier has not been contacted by the US attorney’s office,” says Ron Soffer, a Paris-based lawyer representing Bouvier.