Four Roman sculptures are to be withdrawn from auction tomorrow amid claims that they were stolen from archaeological sites overseas.
Photographs seized by police suggested that the sculptures – funerary busts and a marble statue of a youth from the second century AD – were illicitly excavated, archaeologists told the Guardian.
A spokesman for Bonhams auctioneers said: "Whenever a serious question is raised about an item's provenance we withdraw it from sale pending an internal investigation. We take rigorous care to ensure that we only sell items that have a clear provenance."
Dr David Gill, reader in Mediterranean archaeology at Swansea University, said that the four antiquities bore soil traces that indicated they were excavated during illegal digs. Images in the Bonhams auction catalogue show the same sculptures cleaned and restored.
Archaeologists remain concerned about illegal trading of antiquities and some believe insufficient checks are carried out into their provenance.
Lord Renfrew, the eminent Cambridge archaeologist, warned that "such sales are maintaining London's reputation as a clearing house for looted antiquities".
Gill said the withdrawal was the latest in a series of such incidents in London.
Christos Tsirogiannis, a researcher at Cambridge University and formerly an archaeologist with the Greek ministry of culture, uncovered the evidence suggesting that the sculptures had been illegally excavated. They had been moderately valued, at about £40,000, but he is concerned about the impact of illicit excavations.
He said: "The destruction leaves objects out of context. Even if [an object] is a masterpiece, our duty is to give people history." It is a view shared by most archaeologists.
Since 2003, it has been a criminal offence to deal in "tainted cultural objects", punishable by up to seven years in prison. Renfrew called for auction houses to identify the vendors of antiquities. "That would be a step towards clarifying the problem," he said.
The style of the Roman busts suggests they are of eastern Mediterranean origin and were possibly dug up in Syria or northern Greece. The marble statue probably originates from Italy, archaeologists said.
The Bonhams spokesman said that the firm sends its catalogues for scrutiny to the Art Loss Register – a computerised database – to ensure that only items with clear provenance are sold. "If they raise issues, we also withdraw items," he said.However, Dr Gill said that the Art Loss Register only dealt with stolen items, and not antiquities that may have come from illegal excavations.
