Vienna -- The body of a German billionaire whose father made his fortune using slave labor from Nazi concentration camps has been stolen from his Austrian grave, his family said Friday.

The theft of Friedrich Karl Flick's remains from the family grave in the southern Austrian town of Velden was discovered in mid-November, but despite intensive police enquiries, there has been no breakthrough in the case.

As a result, the family has offered a 100,000-euro (126,000-dollar) reward for information on the thieves -- who succeeded in shifting a 100-kilogramme (200-pound) stone slab in order to make off with the coffin.

In 1991, kidnappers sought a five-million-euro ransom for Flick's brother-in-law, before police freed the hostage.

Friedrich Karl Flick Jr. was ranked 94 among the world's richest people in 2006, the year he died, by Forbes magazine.

His father, coal and arms magnate Friedrich Flick, put at least 40,000 forced laborers from countries occupied by the Nazis to work in his sweatshops.

Friedrich Flick was one of Adolf Hitler's most important arms suppliers and his corporation controlled the coal and steel industries of all Nazi-occupied Europe.

At the Nuremberg Trials after the war, he was sentenced to seven years in prison in 1947 but pardoned in 1950. By the 1960s, thanks to Germany's postwar "economic miracle", he was again one of the richest men in the country.

In 2004, Jewish leaders criticized the exhibition in Berlin of a spectacular art collection assembled by Friedrich Christian Flick, a grandson of the war profiteer, amid criticism that his contemporary masterpieces were amassed with "blood money".

Flick Jr. was himself caught up in a political scandal in the 1980s when he received tax favors for political donations.

AFP/Expatica