The Ministry of Defence and the National Archives were under increasing pressure this week to release papers relating to Yitzhak Persky, the father of Israeli president Shimon Peres, who was held in a prisoner of war camp for British soldiers at Auschwitz.
Robert Halfon, the Conservative MP for Harlow, has written to Defence Secretary Philip Hammond asking for his help in releasing Mr Persky's service record.
The young Polish Zionist from British mandate Palestine joined the Royal Engineers as a sapper on the outbreak of war but was captured in Greece, where he possibly took on the identity of a fallen comrade from New Zealand. He spent the rest of the war in various PoW camps across Nazi occupied Europe.
The Israeli president has previously spoken publicly about his father being held in Lamsdorf, a massive facility in Silesia of which the Auschwitz camp was a satellite. His autobiography states that his father was held near Auschwitz.
Any new documents about Mr Persky are likely to shed light on the story of his close friend Sergeant-Major Charles Coward, who was honoured as a righteous gentile for the help he gave to Jews held in Auschwitz.
The Peres family remained in touch with Mr Coward after the war and helped him find work via Chaim Morrison, deputy chair of the predecessor organisation to the United Jewish Israel Appeal.
German documents held by the Wiener Library show that as of December 1943, the camp at Teschen, which had taken over from Lamsdorf, held 10,537 British prisoners, of whom more than 772 were identified as Jewish.
The files also contain a complaint to the Swiss legation in Germany about the cold-blooded shooting of two British Jewish PoWs called Krauze and Eizenberg.
Researchers at Yad Vashem and the Auschwitz-Birkenau State Museum have agreed to help the JC in its hunt for further details on the British prisoners of war in Auschwitz.
The Ministry of Defence and the National Archives have yet to issue a statement about the whereabouts of any unopened files.