State Justice Minister Beate Merk says Gustl Mollath was and still is dangerous. He was acquitted of attacking his wife, but sentenced to compulsory psychiatric care, after an evaluation found that he had developed a "paranoid system of thought."
In an interview with Sunday's Süddeutsche Zeitung, law professor Henning Ernst Müller said major mistakes were made during Mollath's trial in 2006.
Three years earlier, in 2003, Mollath accused his wife and other employees at the HypoVereinsbank (HVB) of illegally funnelling clients' money into bank accounts in Switzerland. To bolster his claims, he offered up a folder full of documents.
But prosecutors did not investigate - and later, Mollath's wife filed suit against her husband for physically attacking her.
According to Müller, a professor of criminal law at the University of Regensburg, she had strong motivation to make false allegations against him.
Last week Merk defended prosecutors' decision not to probe the corruption claims against Mollath's wife, saying they did not have reasonable suspicion to believe the allegations based on the material provided.
Yet an audit conducted by HypoVereinsbank in 2003, which was only recently made public, suggests prosecutors had good cause to doubt the credibility of Mollath's wife.
"All verifiable claims were found to be accurate," the Süddeutsche Zeitung cited the HVB report as saying.
Müller told the paper that the justice minister had a responsibility to instigate an independent review of the case.
The bank's report means that Gustl Mollath's supposed crimes must be seen "in a completely different light," Müller argued. He also criticised the court for disregarding the allegations against Mollath's wife in evaluating her testimony.
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On Wednesday, the Social Democrats in Bavaria's state parliament threatened to open an inquiry into the matter - but Merk has hit back, accusing the opposition of using the case for political gain.