It’s rare that art deals gone wrong wind up in criminal, rather than civil, court. But English art dealer Timothy Sammons, age 61, appeared at his arraignment in New York State Supreme Court this afternoon flanked by court officers and with his hands cuffed behind his back. Prosecutors are calling for the former Sotheby’s specialist to serve five to 15 years in prison for allegedly stealing millions of dollars from clients who had entrusted him with works by artists including Pablo Picasso and Marc Chagall.

“As alleged in the indictment, the defendant used his industry experience to gain the trust of prospective art sellers, then betrayed that trust by pocketing the proceeds of those sales to fund his own lavish lifestyle,” Manhattan district attorney Cyrus Vance said in a statement. “Not only did victims lose millions of dollars, but many lost valuable pieces of artwork that had been in their families for generations.”

Sammons has been charged with multiple counts of grand larceny in the first and second degrees and one count of scheming to defraud in the first degree.

The district attorney asserts that between 2010 and 2015, Sammons, an art dealer with offices in New York and London, defrauded five victims in the US, the UK, and New Zealand. In court on Friday, assistant district attorney Kevin Wilson said the stolen artworks were worth tens of millions of dollars. He called Sammons, who allegedly defrauded his clients of works including Pablo Picasso’s Buste de Femme, Marc Chagall’s Reverie, and Paul Signac’s Calanque de Canoubiers, “a significant flight risk.”

Sammons allegedly used proceeds from the sale of one victim’s art to pay other clients and used art that did not belong to him as collateral to obtain personal loans.

Glenn Hardy, Sammons’s attorney, pleaded with Judge Felicia Mennin to allow Sammons to post bail, saying it would be very complicated to compile the records necessary to mount his defense if he were sent to jail. He argued that Sammons—whose passport has been seized and who voluntarily turned himself in to US Marshals—was not a flight risk.

Moreover, he pointed out that while living in the UK after being released on £20,000 bail, Sammons had submitted willingly to restrictions on his travel imposed by the UK’s Insolvency Service and that those restrictions had gradually been lifted due to his compliance.

“This is going to be a complex and detailed case in which Mr. Sammons has entered a not guilty plea and will maintain his innocence throughout,” Hardy tells artnet News.

Judge Mennin declined to set bail and Sammons was taken into police custody after the arraignment. His next court date is scheduled for November 6.