Holocaust historians have hit out at the Austrian government after a Jewish writer, who catalogued the state's failure to return properties seized by the Nazis, was jailed in Vienna.
Stephan Templ, 54, has begun a one-year sentence for defrauding the state.
He was convicted in 2013 after omitting the name of an estranged aunt in an application on behalf of his mother for the return of property seized in 1938.
But legal experts said it was not his responsibility to find other heirs.
The lengthy case has drawn widespread condemnation amid allegations Austria has not done enough to return property looted under the Third Reich.
Historian Efraim Zuroff, renowned for his efforts at bringing Nazi war criminals to court, told the BBC on Tuesday the jailing of Templ was "absolutely outrageous".
Meanwhile, Templ's lawyer, Robert Amsterdam, described it as "outright injustice".
Vienna prosecutors have not commented on the case.
Templ, a leading critic of Austria's restitution record, caused controversy in Austria in 2011 with a book called Our Vienna: Aryanization Austrian-Style.
The book, co-written with historian Tina Walzer, documented properties in the Austrian capital - including apartment buildings, cinemas and even a ferris wheel - that were confiscated from their Jewish owners.
Image copyright Getty Images
Image caption Nazi soldiers and party members watch Jews being forced to scrub the pavements of Vienna in March 1938
One of the buildings was a sanatorium owned by Templ's relatives, Lothar Fuerth and his wife.
When Austria was annexed to Nazi Germany in March 1938, Lothar Fuerth was forced to clean the pavement in front of the hospital using toothbrushes as part of the mass persecution of Vienna's Jews. The couple later made their way back into the building and took their own lives.
Image caption Lothar Fuerth was made to clean the pavement outside the sanatorium
In 2006, Templ made a claim on behalf of his mother to a share of the property's value - but failed to specify the name of an aunt, who also had inheritance rights.
Templ told the Guardian: "Owing to the fact that the state stole the property from my family, the obligation should be on them to track down the relatives.
"My only obligation as far as I was concerned was to assure those deciding on the restitution that my mother's claim was bona fide."
Vienna's Regional Criminal Court originally sentenced him to three years in prison in 2013 after the government argued the aunt could have given her share over to the state. The sentence was later reduced to one year.
In September Austrian President Heinz Fischer rejected a request for clemency, saying the punishment was fair because the court had ruled that Templ had "damaged Austria" by his actions.
'Touched a nerve'
Critics have called the decision to jail the writer an "overreaction" and have suggested it may be linked to his criticism of the government's restitution record.
"A lot of people wanted revenge," said Mr Amsterdam, a leading human rights lawyer who defended Russian oligarch Mikhail Khodorkovsky.
"A lot of people are angry at Stephan for the book."
Karl Pfeifer, a veteran Austrian journalist and a Holocaust survivor, has been quoted as saying: "The only reason Templ was prosecuted is that he touched a nerve with his book, which reminded the Austrians of how they stole Jewish property."
Speaking to the BBC after his client went to jail on Monday, Templ's lawyer described his shock that the jail sentence was being served.
"It was a difficult day for me not only as a lawyer but as a witness and a Jew," Mr Amsterdam said.
Image copyright Getty Images
Templ revealed in his book that the ferris wheel in Vienna's Prater amusement park was seized from its Jewish owner who was killed at Auschwitz
Meanwhile Efraim Zuroff, one of 75 Holocaust historians who signed a letter urging the government to cancel the sentence, criticised Austria's handling of cases relating to the Third Reich - including the prosecution of Nazi war criminals.
"This a country that has a really very twisted way of dealing with Holocaust related issues," he said.
We invite all lodges to write to the local Austrian embassy.