In a controversial trial, Stephan Templ was found guilty of defrauding Austria because a restitution application he filed on behalf of his mother omitted the name of his mother's estranged sister, who would have been entitled to a share of the value of the property which was seized from his Jewish relatives in 1938.
Templ, 54, who began his sentence on Monday has said the case is “completely absurd” and borders on anti-Semitic persecution.
In the latest developments, he told the Kurier newspaper that he had been denied kosher food in prison and that he had to ask his girlfriend to contact the Jewish Community in Vienna to provide proof of his Jewishness.
The Kurier reports that under Austrian prison law you are only registered as Jewish if Austria's Jewish Community has officially recognised you as a religious member. Templ's main residence is in Prague.
The head of Simmering prison, General Josef Schmoll, confirmed that since Wednesday evening Templ has been receiving kosher food.
Templ has been a vocal critic of Austria's attitude towards returning properties stolen from their Jewish owners by the Nazis, and wrote a book called Unser Wien, which catalogued hundreds of properties seized from Jewish families that were never returned.
The property at the centre of his case is a 19th century villa near the Ringstrasse in Vienna, that was once a private birth clinic belonging to a cousin of Templ's grandmother.
Legal experts have said Templ was never under any legal obligation to contact other heirs to the building - and that that was the duty of the arbitration panel. Templ's lawyer, Robert Amsterdam, has said the case is an “affront to justice” and full of flaws.
Seventy-five Holocaust historians from around the world have signed a letter to the Austrian government, urging it to cancel Templ's prison sentence.