(Bloomberg) -- Duet Group Chief Executive Officer Henry Gabay, who was apprehended last month in France at the request of Cologne prosecutors pursuing a Cum-Ex probe, was released shortly after arriving in Germany Thursday.

Duet said in a statement that all European warrants against Gabay were dropped after a short procedural hearing in a German court. The Duet CEO posted a security deposit but didn’t say how much it was.

The company said that Gabay “offered his full assistance to the German authorities in their future inquiries into the Cum-Ex investigations, while reiterating that he had no role in any tax fraud or any dividend arbitrage trading.”

“Mr. Gabay has not been charged with any offense and is back to his work continuing to lead the Duet Group,” the London hedge fund company added.

A spokesman for Cologne prosecutors said he can’t immediately comment, while the press office for the Bonn Local Court didn’t immediately return a call.

Gabay’s lawyer Robert Unger didn’t immediately reply to a request for comment.

Probes into the discredited tax strategy -- which may have cost Germany more than 10 billion euros ($11.4 billion) -- have already resulted in the conviction of two bankers, who are appealing the verdict. In addition, four M.M. Warburg & Co. bankers were indicted last month.

At a hearing in Aix-en-Provence earlier this month, a judge said that the German prosecutors suspected the Duet CEO had involvement with an alleged fraud that took part, between 2009 and 2011, and “made the German state about 94 million euros poorer.” Gabay said in Aix that he had “nothing” to do with it.

Cum-Ex transactions took advantage of a now-abandoned method of taxing dividends, which seemed to allow multiple tax refunds through a combination of short sales and other transactions.

While the move against Gabay and another Duet official were the first outward signs that German prosecutors are accelerating their probe as they faced looming deadlines from a 10-year statute of limitations and Brexit, lawyers expect other companies and individuals that be looked into.

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