Further details have emerged in the case against Helge Achenbach, the leading German art advisor who was arrested on 10 June on suspicion of fraud. According to the German business newspaper Handelsblatt, which cites the 24-page criminal complaint, Achenbach is accused of allegedly defrauding the late Aldi-supermarket heir and art collector Berthold Albrecht of €18m. There is also “early suspicion” that Achenbach allegedly defrauded another client, says Anette Milk, the senior public prosecutor in Essen.

A valuation of the Albrecht’s estate following his death two years ago raised concerns, and the collector’s heirs filed a complaint with the state prosecutor’s office in Essen, in April.