Thousands of paintings and antiques stolen by the Nazis and others remain in circulation on the art market, but just occasionally one gets returned to its rightful owner.

Manuela Saragosa speaks to two grateful beneficiaries. Penny Ritchie Calder is a warden at St Olave's church in London, which recently regained the 17th century statue of noted botanist and congregant Dr Peter Turner, while Sylvie Sulitzer got back a Renoir painting that belonged to her art dealer grandfather, in both cases some 70 years after they were stolen.

Professional art detective Chris Marinello of Art Recovery International guides us through the murky world of stolen artwork, while Lucian Simmons of the global auction house Sotheby's explains what the restitution department he heads is doing to identify and recover these items.

Producer: Laurence Knight

(Picture: Sylvie Sulitzer poses with the recovered Renoir painting "Two Women in a Garden" in New York; Credit: Spencer Platt/Getty Images)