Local media reports indicate that authorities raided the establishment over suspicions that the 26 paintings were forgeries and had falsified documents. After the auction house handed over the works, investigators also collected an additional 37 paintings over similar concerns.
German news outlet Süddeutsche Zeitung reported that police were acting on the advice of an art expert who informed investigators that the expert opinions cited by the auction house regarding the paintings' authenticity were "doubtful."
The confiscated works will remain in police custody until the investigation is completed. Police will be working to determine if the paintings are in fact original Hitler works, and, if they're found to be illegitimate, determine if estates that worked with Weidler were aware that the paintings were phonies.
Forged documents can land individuals in prison for up to five years in Germany.
Chief Prosecutor Antje Gabriels-Gorsolk told the Süddeutsche Zeitung that auction house employees will also be interviewed as witnesses for the duration of the investigation.
The confiscated works, which came from the collections of private owners, were a variety of watercolors, oil paintings and sketches. According to AFP, they mostly depicted buildings, nature scenes and nude women, including Geli Raubal, Hitler's half-niece.
Following the development, Weidler issued a statement to eventgoers, informing them that 26 paintings had been removed from the Saturday auction list, but that five others inscribed with "A. Hitler" would still be available for interested parties.
Additionally, a vase, a wicker armchair and a tablecloth believed to have belonged to Hitler remain up for grabs.
Prior to the seizure, Weidler noted in a catalogue for the special auction that the bidding would include "pictures signed or monogrammed" by Hitler, spanning a period from 1907 to 1936. One of the most expensive paintings was listed with a starting bid of roughly $51,000, and the lowest figure for a work was marked at an estimated $150, the Washington Post reported.
German laws allow the trade of Hitler's artworks as long as prohibited symbols, such as the swastika, do not appear in them. However, despite the legality of selling them, such works are often seized over suspicions of fraud.
In late January, German police seized three other paintings from the Kloss auction house in Berlin, claiming they, too, were forged. The three watercolor paintings, dated between 1910 and 1911, were of Alpine and Rhenish landscapes.