The auction house Bonhams is facing calls to withdraw a Roman antiquity from its forthcoming London auction amid claims that it was looted from Turkey.
A third-century Roman silver plate, decorated with a depiction of a river god, is lot 62 of the 5 December auction and is estimated to sell for between £20,000 and £30,000.
But Dr Christos Tsirogiannis, an affiliated archaeology lecturer at the University of Cambridge and an expert on trafficking networks for looted antiquities, has evidence that Turkish traffickers supplied it in 1992 to Gianfranco Becchina, convicted in Italy in 2011 of dealing illegally in antiquities and twice in Greece in recent years.
Becchina’s archive was seized by the police and shared with Tsirogiannis by the late Paolo Giorgio Ferri, who prosecuted traffickers in looted antiquities in Italy. The documents extend to thousands of images and other material seized from dozens of traffickers.
Those relating to Becchina detail the Roman plate and the traffickers who sold it to him, showing that it was part of a group of Roman silver objects found together, for which he paid $1.6m (£1.3m). They detail payments in instalments and even bank accounts.
Tsirogiannis leads illicit antiquities trafficking research for the Unesco chair on threats to cultural heritage at the Ionian University in Corfu. Over the past 18 years, he has identified more than 1,700 looted antiquities, alerting police forces and playing a significant role in their repatriation.
A spokesperson for Bonhams said it had confirmed the provenance of the object in line with its procedures.
In June, Tsirogiannis spoke out when the same Roman plate was offered as lot 57 for sale by Bonhams for an auction in July. He suspected its link to Becchina but had only a poster of it from the dealer’s archive. His subsequent research uncovered documents relating to Turkish traffickers, including photographs of the plate in an unrestored condition in Becchina’s possession.
In July, Bonhams announced that it had sold the plate for about £74,000, more than double its estimate.
Tsirogiannis has also linked a monumental Roman marble portrait bust of Emperor Hadrian, lot 61 in the same Bonhams auction, to Becchina.
The auction’s provenance or collecting history refers vaguely to the “Swiss art market”. Becchina was based in Basel and his seized archive features the head in one of his letters and in photographs.
Tsirogiannis said: “Bonhams appears not to have conducted basic provenance research, which would involve checking with the relevant authorities on whether particular antiquities may have been looted.
“The Italian and Greek authorities have the same Becchina documents, but they were strikingly silent after I published my research last July. Its previous appearance in the same auction house just a few months earlier is also not recorded in the provenance.”
Francesca Hickin, the head of antiquities at Bonhams, said: “It would be in our shared interest for the contents of the Becchina archive to be made accessible to auction houses, as this is currently not the case.
“Bonhams has confirmed the provenance for these two items, which is both printed in the sale catalogue and is also in the public domain.
“The plate was in Bonhams’ antiquities sale in July and was sold, although the buyer failed to pay in the stipulated timeframe and so the plate is now being re-offered in the December sale, at the request of the consignor.
“We have strict procedures in place to help us ensure that we offer for sale objects that we are legally able to sell. We have had no communication from any law enforcement agency regarding these items.”
