 The National Gallery has also been criticised for <unk> paintings . Kenneth Clark 's decision in 1939 to <unk> a group of paintings by anonymous artists of the Venetian school as works by Giorgione ( a crowd @-@ pulling artist due to the rarity of his paintings ) made him unpopular with his staff . More recently , the attribution of a 17th @-@ century painting of Samson and Delilah ( bought in 1980 ) to Rubens has been contested by a group of art historians , who believe that the National Gallery has not admitted the mistake to avoid embarrassing those who were involved in the purchase , many of whom still work for the Gallery . 
