Historians always believed it to be an oil painting by Sir Anthony van Dyck. But when the artwork was sent away for treatment at the National Trust's Royal Oak Conservation Studio at Knole House ...

Entitled "Crude Oil (Vettriano)" and sometimes called "Toxic beach," the painting first revealed by Banksy in 2005 was sold at Sotheby's in London, from the collection of Mark Hoppus, bassist with ...