Lifting the veil that has obscured one of the art world's most tantalizing mysteries, Russia's Culture Ministry has revealed that a valuable Dutch art collection looted by Soviet Army as a "war trophy" at the end of World War II is on Russian soil.


The missing Koenigs collection, thought to be worth up to $100 million, consists of 492 drawings by masters such as Rembrandt, Diirer, Rubens and Cezanne.


It is the second significant "war trophy" collection that Russia has acknowledged holding in the last week. The first, which consists of 300 drawings and also includes Rembrandts, was brought from the north German city of Bremen after the war.


The exact location of the Koenigs drawings is still secret, but the Dutch ambassador to Moscow, Joris Vos, said Monday that he expected to see the drawings any day.


Speaking on Dutch television, Russia's culture minister, Yevgeny Sidorov, confirmed for the first time late last week that the drawings were in Russia.


"I can say that we have found the collection", he said. "I can not name the place, because I first have to see and identify the collection myself".


Vos called Sidorov's statement "an important first step". The next phase, he said, would be to bring the drawings to the Netherlands. The ambassador said Sidorov had personally assured him that the meeting would take place by the end of this month.


In the Netherlands, there is still confusion as to whether or not the drawings will be returned to the Boymans-van Beuningen museum in Rotterdam. The remaining 34 drawings of the Koenigs collection, which have been recovered piecemeal since the war, are kept in the museum.


The Russian Culture Ministry's policy on returning "war trophy" art is also still unclear. The collection looted from Bremen apparently will not be returned to Germany until Russia has assessed its own cultural losses from the war.


Last Friday the Dutch newspaper NRC Handelsblad reported that the Russians might claim back Russian art presently in the Netherlands.


According to the article, first the Soviet and then the Russian Culture Ministries have threatened for 18 months to retrieve paintings by Kazimir Malevich currently exhibited at the Stedelijk museum in Amsterdam. The works by the Russian painter were bought by the museum's director in the 1950s.


The embassy, however, says the report was incorrect.


"The ministry has been very cooperative and has made no claims", said Andre Carstens, cultural attache at the Dutch Embassy.


"The Malevich paintings were legitimately bought", Carstens added. "After all, there are numerous Rembrandts in the Hermitage, which the Dutch aren't claiming either. That would be absurd".


The fate of the Koenigs collection itself has all the elements of a detective story, stolen first from the Netherlands and then from Germany and leaving potential for complicated wrangles over its ownership.


During the war, numerous works of art were stolen by the Red Army, which regarded the looting as compensation for the enormous losses the Soviet Union had suffered.


Special "trophy commissions" of art experts dressed in military uniforms were set up to bring home "war trophies" -- works of art robbed from German museums. The Soviets justified the practice by saying that Nazi troops had done the same in Russia. As a result, almost every museum in the Soviet Union had a trophy fund.


But Carstens insisted that the Koenigs collection, could not possibly be regarded as a war trophy.


"The collection was taken by mistake", he said. "The Red Army regarded it as being German and therefore thought they were taking home a war trophy".


Franz Koenigs, a German banker living in Haarlem near Amsterdam, sold the collection in 1940. The buyer was a wealthy harbor industrialist from Rotterdam, D. G. van Beuningen, who in turn sold the art to Hans Posse, Hitler's art expert.


Posse was collecting art from all around occupied Europe for a "Fuehrer museum" which would be set up in Linz, Austria. He sent the Koenigs collection on to the Dresden Gallery in Germany, where it was confiscated by the advancing Soviet Army after the war.


Dutch authorities do not expect Germany to make any claims. Robert de Haas, director of the Netherlands Office for Fine Arts, told the Dutch media on several occasions that the question of ownership was therefore clear.


"It is irrelevant whether or not van Beuningen voluntarily parted with the collection", NRC Handelsblad quoted him as saying. "What matters is that the Dutch govemment-in-exile in 1940 has declared all transactions with the Germans as invalid, a decision which was confirmed by the Allied Forces".


For now, experts can only guess at where the drawings have been hidden for the past 50 years. The Dutch Office for Fine Arts believes that they are now in the vaults of Moscow's Pushkin museum or on the monastery grounds of Sergeyev Posad, formerly Zagorsk.