Yad Vashem has issued an apology for the “partial picture of historical facts” in the World Holocaust Forum attended by dozens of world leaders in Jerusalem last month.

The message from Israel’s official authority for commemoration and research of the Holocaust appeared in a letter to Haaretz signed by Professor Dan Michman, head of Yad Vashem’s International Institute for Holocaust Research.

He did not specify who was responsible for the “inaccuracies”, but wrote that films shown at the event made “no mention of the division of Poland between Soviet Russia and Nazi Germany in 1939, or the conquest of Western Europe in 1940.”

“In addition, maps that were presented had mistaken borders of Poland and its neighbours and the wrong identification of concentration camps as extermination camps,” he added.

The World Holocaust Forum is organised by the European Jewish Congress, which is presided over by Moshe Kantor, a Russian businessman with close ties to the Kremlin.

It has been held in various locations over the years and this year, to coincide with the 75th anniversary of the liberation of Auschwitz, it was jointly hosted by President Reuven Rivlin and Yad Vashem in Jerusalem.

The film Prof Michman mentions in his letter presented a partial narrative of the Second World War that omitted to mention the Molotov-Ribbentrop Pact between Germany and the Soviet Union, and the subsequent occupation of Poland by both countries.

This fits with the version of history taught in Russia to this day, which states the war only began in 1941 when the Soviet Union was invaded by Germany.

All mention of the two countries’ previous collaboration has been airbrushed from textbooks.

High-level delegations from 40 countries attended the event in Jerusalem, including one led by Russian President Vladimir Putin, who spoke at the ceremony in Yad Vashem.

Poland, however, boycotted the event when its government was informed that President Andrzej Duda would not be invited to speak.

Mr Duda said in an interview with Israeli media that the place to hold a memorial event for Auschwitz was at the site of the camp in Poland.

There was considerable disquiet in Yad Vashem ahead of the event at the way the ceremony was being seen to serve the Russian narrative, but Prof Michman’s letter is the first public acknowledgement.

Mr Kantor is a major donor of Yad Vashem and the Israeli government gone to particular lengths in recent years to bolster ties with Mr Putin, whose air force now controls the skies above neighbouring Syria.

This is not the first time in recent years that Yad Vashem’s historians have been forced to make controversial interventions to set the historic record straight.

In 2015 they contradicted a speech by Prime Minister Benjamin Netanyahu in which he had said that the Palestinian mufti Haj Amin al-Husseini had given the Germans the idea to exterminate European Jewry in the Final Solution.

Three years later, Yad Vashem’s historians criticised a joint statement signed by Mr Netanyahu and Polish premier Mateusz Morawiecki that downplayed the collaboration of Polish citizens with Nazi persecution in the Holocaust.