Otto Wacker became an art dealer in 1925 after various false starts in other professions. He developed a reputation for reliability in the art field. The fraudulent Van Goghs were probably the work of his brother, the painter and restorer Leonhard Wacker.
Wacker managed to convince prominent Van Gogh experts Jacob Baart de la Faille, Hendrik P. Bremmer, Julius Meier-Graefe and Hans Rosenhagen that the paintings he was selling were genuine. The experts accepted his tall tale that a Russian had bought the paintings, transferred them to Switzerland illegally, and had commissioned an illegal agent to sell them. Experts understood the need for this Russian to remain anonymous in order to prevent reprisals from relatives who still lived in Soviet Union and supplied certificates of authenticity without proof of provenance. Thannhauser, Matthiesen and Goldschmidt galleries bought some of the paintings.
Wacker's paintings were to be exhibited in January 1928 in Cassirer Exhibition by the firm of Paul Cassirer in Berlin. It was organized to coincide with the publication of de la Faille's standard catalogue of Van Gogh's work. When Wacker delivered the last four paintings, Grete Ring and Walter Feilchenfeldt, the general managers of the exhibition, noticed the differences and recognized them as fakes. The canvases were returned to Wacker.
Further investigation revealed 33 suspect paintings, all of them supplied by Wacker. Galleries that had sold his paintings asked their customers to return them. Hugo Perls, an art dealer and lawyer who had bought several paintings, still insisted that they were authentic. In December 1928 the Matthiesen gallery, with the aid of the Federation of German Art and Antique Dealers, sued Wacker. De la Faille, who had contacted the Van Gogh estate, changed his mind and listed the paintings in Les faux van Goghs (The False Van Goghs), published 1930.
The trial against Wacker began on 6 April 1932. Vincent Willem van Gogh, nephew of the painter, gave the first evidence at the trial and stated that family records did not include any Russian who would have purchased any paintings. De La Faille, on the other hand, had changed his mind once again and claimed that 5 of the paintings were genuine.
During the trial, various experts did not come to full agreement on what paintings were authentic (and the argument was to continue in some circles for years afterwards). Bremmer argued that at least 9 paintings were genuine. Meier-Grafe admitted his mistake and even that the expert opinion could be fallible. Hans Rosenhagen said that 14 of the works were inferior but genuine.
However, the Dutch restorer A M de Wild found that the pigments used in the paintings were not similar to those Van Gogh had used. Art restorer Kurt Wehlte showed with X-rays that the painting techniques were different (although he used a painting that was declared a forgery in the 1970s). Later it was found that the paintings had not been painted on French canvases at all.
On 19 April 1932 Wacker was charged with fraud, and after an appeal, was sentenced to 19 months in prison and a fine of RM 30.000.
Some former directors of the Bank für Deutsche Beamte, who had been speculating in the paintings on behalf of the bank, were sued.
After World War II, Otto Wacker lived in East Berlin. He had abandoned the art market. Some paintings have since disappeared but nowadays Van Gogh experts agree that none of them are genuine.
- Grete Ring, Der Fall Wacker, Kunst und Künstler, May 1932, pp. 153-165; see Stefan Koldehoff, The Wacker forgeries: a Catalogue, Van Gogh Museum Journal 2002, pp. 138-149
- For Hugo Perls' view of the Wacker affair see: Hugo Perls, Warum ist Camilla schön? Von Kunst, Künstlern und Kunsthandel, München 1962. pp. ???.
Koldehoff, Van Gogh. Mythos und Wirklichkeit, Köln 2003.