PARIS — Stephan Templ was hoping to right a historic wrong when he fought to reclaim part of an imposing Victorian hospital that was looted from his family by the Nazis in 1938, he says. Instead, he now faces three years behind bars.

Mr. Templ, 53, a bookish freelance journalist, has been convicted of defrauding the Austrian state of some 550,000 euros, or $760,000, by willfully omitting his estranged aunt, Elisabeth Kretschmer, 84, from the restitution claim he made on behalf of his 80-year-old mother in 2005. He is preparing an appeal to the European Court of Justice in Luxembourg.

Now, depending on who is doing the talking, the case has become either an example of wrongful imprisonment, naked avarice or how feuds among multiple heirs can undermine justice in Holocaust restitution cases.

Austrian prosecutors argue that dissembling and greed are to blame for Mr. Templ’s predicament. But Mr. Templ made his name exposing Austria’s struggle to come to terms with its Nazi past, and he insists that the verdict is the state’s retribution.