The court found that Achenbach charged unlawful levels of commission on the purchase of vintage cars and paintings just before the death of Berthold Albrecht, whose father, Theo, built the Aldi empire.
Although Achenbach’s lawyers in the civil case argued that the commission was based on a verbal agreement between their client and Albrecht, the judge found that no such agreement existed.
“No economically savvy person would have agreed to such a completely opaque pricing structure,” said the judge, Joachim Matz, adding that the family was likely to sue the art dealer for an additional 5 million euros over other commissions.
Achenbach also faces fraud charges in a criminal trial in the west Germany city of Essen. He is accused of doctoring accounts and receipts in financial transactions, charges which he denies.
Achenbach, who is currently in custody pending the outcome of the fraud trial, has the option to appeal Tuesday’s verdict.