According to Bloomberg, the indictment targets the trio, two German nationals who also worked at HVB and Hanno Berger, who was regarded as one of German's most profitable tax attorneys before the investigation kicked off.
Bloomberg says prosecutors see Berger as the brains behind the scheme.
The investigations come as part of the "cum-ex" scandal in Germany, which has seen many banks implicated in conducting these outlawed transactions.
In a "cum-ex" transaction, two parties are able to claim ownership of shares, enabling both to claim tax rebates, despite the fact that there is only one set of shares. This ruse most often plays out in short-selling, where the actual holder of shares and someone who bought them from a short-seller can both claim tax credits on a dividend paid only once.
German authorities closed the loophole in 2012, but some banks continued to engage in the practice. The scandal has escalated to now involve more than 100 German banks.
Bloomberg reports that in Mora's case the bankers and Berger cooperated with a German businessman who acted as the investor buying the stock. He applied for the tax refunds and the profits were then split between the parties.
According to the Companies Office, Mora continues to have a number of business interests in New Zealand and is listed as a director of K&C Christchurch, MANDM Properties Limited and CSA Christchurch.
He was formerly also listed as a director of MC Christchurch Holdings and M Family Holdings.
If found guilty the accused could spend up to 10 years in prison.