Deutsche Bank on Thursday confirmed a net loss of 6.8 billion euros last year, as Germany's top lender was weighed down by enormous restructuring costs, risk provisions and lower income.

Losses in the fourth quarter alone amounted to 2.1 billion euros ($2.3 billion), said Deutsche Bank, which had already published most of its financial results last week.

The bank is currently mired in a tangle of around 6,000 lawsuits and in May was fined a record $2.5 billion for its involvement in rigging interest rates.

It has also faced probes by Swiss authorities for suspected price fixing on the precious metals market and US investigators have looked into its Moscow branch on suspicion of possible involvement in money-laundering.

The group's new chief John Cryan has pledged a sweeping culture change within the bank, but investors are worried that the litigation costs will still hit profitability for years to come.

Despite the heavy restructuring costs, Cryan vowed to continue on the same road.

"We know that periods of restructuring can be difficult. However, I am confident that by continuing to implement our strategy in a disciplined way, we can transform Deutsche Bank into a stronger, more efficient and better-performing institution," he said in a statement.

"We are concentrating on 2016 and we are continuing our work to settle our litigation. The work of restructuring and investing in our platforms will continue this year," vowed the chief executive.