The latest development adds to Deutsche Bank's long list of legal headaches.

Deutsche Bank said this week it is working with Russian tax authorities over investigations into back taxes potentially owed by the lender, just weeks after it spent millions of dollars resolving a major money laundering scandal related to the country. 

The Russian unit of Germany's largest lender allegedly bought foreign currency on its domestic market and then transferred this money to its London unit to lower its taxable income.

The Frankfurt-headquartered bank's Russian unit earlier this week said it was undergoing a routine audit and was cooperating fully with the involved authorities.

“As part of an ongoing routine audit, Deutsche Bank is working with Russian tax authorities on matters relating to standard business operations that follow normal industry practice,” the group's Russian unit said in a statement sent to this publication. 

An insider source reportedly told Russian news service RBC that the tax issue was unrelated to the Russian money laundering case that Deutsche Bank resolved with UK and US financial regulators, which saw the lender shell out a total of $630 million as part of the settlement. 

The development in Russia adds to Deutsche Bank's long list of legal headaches. 

Last week, the managing director of its Israel operation was arrested amid authorities' probes into suspected tax offences.

Last month, Deutsche Bank reached a $7.2 billion settlement with the US Department of Justice over its sale of toxic mortgage-backed securities before the financial crisis. 

The fine will undoubtedly deliver a hefty blow to the bank's balance sheet and it is consequently set to slash up to 17 per cent of staff globally in its equities division as it tries to kick-start recovery efforts, this publication understands.