Germany could owe nearly £620 billion ($850 billion) for the damage it inflicted on Poland during World War Two, a senior Polish official has said.

Arkadiusz Mularczyk is leading a team that is assessing potential reparations to Poland. Germany killed six million Polish citizens during its nearly six-year occupation of Poland.

'We are talking about very large, but justified amounts of compensation for war crimes, for destroyed cities, villages and the lost demographic potential of our country,' Mularczyk told Polsat news.

Poliand says that it has never been compensated by Germany for the massive losses inflicted on it during World War II. Pictured: Two Jewish resistance fighters arrested by German troops after the uprising in the Warsaw Ghetto in 1943

World War II, which began with the German invasion of Poland in 1939, left almost 6 million Polish citizens dead

Ice floats on the river Oder which is the border of Germany and Poland - relations between the two countries have become strained over the compensation issue

'[Because] we are talking about such large amounts, Germany is pursuing a policy that challenges any claims and is conducting this policy around the world.'

Mularczyk argues that Poland, which came under Soviet domination for more than four decades after the war, never received war reparations from Germany.

German parliamentary legal experts said last year that Warsaw had no right to demand reparations. It has repeatedly said there is no legal basis for Poland's reparation claims.

But the Polish ruling Law and Justice party (PiS)argues the Poland deserves compensation through war reparations and the panel led by Mularczyk will estimate how much money is due.

The Pis has invoked Germany’s occupation of Poland during World War Two as part of efforts it says aims to promote patriotism at home and to counter accusations that some Poles were also perpetrators of wartime crimes against the Jews.

Israeli politicians however have accused Poland of attempting to whitewash the role of Poles in German war crimes against Jews during the conflict.

Earlier this week Poland enacted a law that makes it a crime to accuse the Polish nation of crimes that were committed by Nazi Germany.

This Friday, Feb. 18, 2011 file photo, shows the Memorial on the grounds of the former German Nazi Death Camp Treblinka, near the village of Treblinka, north-east Poland

The U.S. and other allies have warned Poland that it is parlously close to denying the crimes of the Holocaust

Poland has insisted that it would never 'whitewash' its history and the fact that some Poles did commit 'ignoble acts' during World War Two

The law is seen by some as part of a larger effort by the nationalist authorities to manipulate history so that the country is not associated with war crimes.

Germany, together with the Soviet Union, attacked and occupied Poland in 1939. Nazis killed most of the 3.2 million Jews that lived in Poland. Damage to the capital alone amounted to £32 billion, according to an estimate in 2004 by city hall.

Poland never surrendered to Nazi Germany and lost about 3 million of its non-Jewish citizens during the war, including many of its intellectuals and elite. The capital Warsaw was razed to the ground by Nazis in 1944 after a failed uprising in which 200,000 civilians died.

The reparations issue has complicated Poland's diplomatic work with Berlin, two sources at the foreign ministry told Reuters.

'Our ties with Germany could be better and this does not help,' one source said.

Poland got nothing in compensation because in 1953 its communist government - under pressure from the Soviet Union - renounced any claim to reparations from the then East Germany, ruled by a fellow-communist regime. West Germany by then had already made payments to Greece, Israel and Yugoslavia.