Sotheby’s has filed a lawsuit in New York against the vendor of a 16th century Old Master painting after it was confirmed to be a fake.

In October last year, the auction house announced it would be conducting an investigation into the painting of ‘Saint Jerome’. Attributed to the ‘Circle of Parmigianino’, it was sold by Sotheby’s New York in January 2012 for US$800,000 (£509,650). Doubts over the work’s authenticity emerged after it was linked to an Old Master forgery scandal, which broke last year.

Vendor Lionel de Saint Donat-Pourrières has refused to return the proceeds of sale from the unframed oil on panel, which amounted to US$672,000 (£546,211). In a statement, Sotheby’s said “While we would have preferred to settle this matter out of court… we have been left no other option than to pursue legal action”. The auction house also stated that it had fully reimbursed the buyer of the work.

According to Sotheby’s, detailed technical analysis by specialist art investigation firm Orion Analytical revealed that the ‘Saint Jerome’ was ‘undoubtedly a forgery’. Forensic art analyst, James Martin, found traces of the modern synthetic pigment phthalocyanine green in samples taken from the painting. The pigment was first used in paints 400 years after the death of Parmigianino and his contemporaries.

The ‘Saint Jerome’ is one of several disputed works believed to have passed through the hands of French dealer Giulano Ruffini who is currently under investigation. Among these works is a ‘Portrait of a Man’ formerly attributed to Frans Hals but since declared a fake. Ruffini sold the portrait for a reported US$3 million (£2.5 million) in 2010.

Negotiations with the seller of the Hals painting are ongoing but already the threat of further litigation is looming. “We hope that the sellers will behave appropriately and fully refund the purchase price that was received from selling a forged work, but we will certainly enforce our rights if necessary”, Sotheby’s told artNet News.