Deutsche Bank co-CEO Juergen Fitschen on Monday denied charges of giving false testimony in a legal battle with the defunct Kirch media group, for which he has been on trial in Germany since April 28.

"At no time did I lie, cheat or try to cheat during the Kirch process, whether before, during or after my deposition," Fitschen said in his first statement to the higher regional court in the southern city of Munich.

A guilty verdict would deal a deadly blow to Germany's biggest lender as it struggles to clean up its image in the wake of a long list of legal challenges in recent years.

Fitschen and four others -- ex-chief executives Rolf Breuer and Josef Ackermann and former executives Clemens Boersig and Tessen von Heydebreck -- are accused of giving misleading evidence to judges in one of the lawsuits brought by the late media magnate Leo Kirch against the bank.

If found guilty, they could face prison sentences of up to 10 years. The proceedings are expected to run at least until September.

Kirch, who died aged 84 in 2011, had accused Deutsche Bank of causing the downfall of his media empire in 2002 when the bank's then chief executive, Breuer, publicly questioned the group's creditworthiness in a television interview.

Breuer, who has yet to take the stand, is the only defendant of the five who has not denied the charges against him.

Prosecutors accuse Fitschen -- who has headed Germany's biggest bank alongside Anshu Jain since 2012 -- and the other defendants of giving false testimony with the aim of having Kirch's lawsuit dismissed.

Fitschen said he did not give "unclear testimony" in the Kirch affair, adding that his remarks were mentioned in the 2012 civil court judgement that ordered Deutsche Bank to compensate Kirch's heirs.

He also denied covering for his colleagues' alleged lies.

The bank is currently embroiled in several different legal battles, with the accusations ranging from manipulation of the currency markets and rigging the Libor and Euribor interest rates, to doing business with countries subject to US sanctions such as Iran.