The story of how one of the wealthiest men in the Netherlands was exposed as a Nazi war criminal. In the 1970s, Pieter Menten was a respected art dealer, but it was revealed that during the Second World War, he had led mass killings in eastern Poland. We hear from Dutch journalist, Hans Knoop, whose investigation into Menten caused a national scandal and finally led to the millionaire's arrest.

Photo: Pieter Menten photographed in 1977.(credit: National Archives of the Netherlands)