The latest raid is a new blow to Deutsche Bank, which has been hammered by a string of scandals linked to its pre-2008 crisis attempts to compete with Wall Street investment banking giants.
German prosecutors raided several Deutsche Bank offices in the Frankfurt area on Thursday over suspicions of money laundering based on revelations from the 2016 "Panama Papers" data leak.
Prosecutors said they were investigating allegations that Germany's biggest lender helped clients set up offshore companies in tax havens to "transfer money from criminal activities" to Deutsche Bank accounts.
Some 170 police officers and investigators from the Frankfurt prosecutor's office were searching six of the bank's premises in and around the city, the prosecutors said in a statement.
Deutsche Bank said it was "fully cooperating" with the authorities on the case which it said was "related to the Panama Papers."
The Panama Papers scandal that erupted in 2016 with a massive data leak from Panamaian legal firm Mossack Fonseca exposed large-scale tax evasion, laying bare how the world's wealthy and powerful stashed their assets in offshore businesses.
Deutsche Bank was among hundreds of financial institutions whose names cropped up in the media reports.
The Frankfurt prosecutors said their probe was focusing on two Deutsche Bank employees aged 50 and 46, as well as several unnamed senior staff members.
Based on information from the Panama Papers, they are accused of "failing to report suspicions of money laundering" linked to offshore firms involved in tax evasion "even though there was sufficient evidence" to suggest illegal activity, prosecutors said.
Prosecutor Nadja Niesen said one of Deutsche Bank's offshore branches on the British Virgin Islands handled transaction volumes worth $354 million (311 million euros) for more than 900 clients.
"There is currently suspicion that most of the money stems from foreign tax offences."
Shares in Deutsche Bank were down 3.4 percent at 8.30 euros in the early afternoon, making them the worst performing stock on the DAX blue-chip index.
TRT World's Ira Spitzer has more details from Berlin.
'Lax money laundering checks'
The raids are the latest embarrassment for embattled Deutsche Bank, which has repeatedly been rapped by regulators for lax money laundering controls.
Markus Meinzer, director of the Financial Secrecy Tax Justice Network, said the "raid is long overdue because the Panama Papers have amply illustrated how offshore law firms cooperated with banks in setting up structures with one single aim: to help clients hide their true identities."
"As banks in Germany manage roughly three trillion euros of interest yielding assets, the potential for abuse is enormous ... Germany owes to the world to clamp down on this dark side of its economy."
In September, Germany's financial supervisor BaFin took the unusual step of embedding auditors from KPMG at Deutsche to monitor the bank's progress in battling illegal transactions such as money laundering, terrorist financing and dealings with organised crime.
In 2017, Deutsche already had to pay a fine of almost $630 million after an investigation by British and American authorities into laundering of money originating in Russia.
Soon afterwards, the US Federal Reserve ordered a further fine of $41 million over gaps in the bank's money laundering surveillance.
Deutsche Bank has also come under scrutiny over its activities as a correspondent for scandal-plagued Danske Bank, Denmark's largest lender.
Citing people familiar with the matter, Bloomberg News had reported that Deutsche was the unnamed bank a Danske whistleblower said had handled almost $150 billion of suspect transactions originating in the Danish firm's Estonian branch.
Deutsche Bank is in the throes of a major restructuring plan, with 7,000 jobs to go by the end of 2019.
The bank said at the end of October that it expected to report a net profit for the first time since 2014, not least because no legal settlements in the hundreds of millions or even billions were on the horizon as in previous years.