He was an Austrian-German economist and attorney-in-fact of the Rotterdamse Bank who spent a part of his life in the Netherlands.
On 22 July 1941, he drew up a will in which he appointed his brother in Ohio in the United States as his sole heir.
In February 1942, Mautner was ordered to move to Tugelaweg in Amsterdam as a result of the forced relocation of Jews.
Various of Mautner's works of art and other possessions were recovered for his heirs, by custodians of his estate after the war.
Three of the paintings that Mautner sold under duress are: The latter two were acquired by the Sonderauftrag Linz and returned to the Netherlands after the war, where they became part of the NK-Collection of the Stichting Nederlands Kunstbezit.
Mautner could not act as a seller, due to his Jewish origin, so he asked his friend Hans Alfred Wetzlar to fulfill the formalities.