The grand opening of a joint German-Russian art exhibition in St Petersburg was spoiled on Friday when Moscow objected to Angela Merkel’s plan to use her speech to refer to hundreds of looted German works of art looted by Red Army soldiers after the war.

The Germans claim that some 1 million looted objects are still missing, including the Treasure of Priamos, objects looted by the Germans in Troy under the direction of Heinrich Schliemann way back in 1873.

Moscow appears to be open to compromise, but only when the Russian artworks destroyed by German troops during World War II – estimated to be more than 110m books and publications following the plundering of 427 Soviet museums and 4,000 libraries – be returned, as well.

“This is a very touchy question for the societies of both countries. We need to look for solutions, rather than inflating the problem.”