Authorities in the Netherlands said the probe related to as many as 55,000 suspect accounts held at a Swiss bank, which officials refused to identify however Credit Suisse later released a statement to confirm its involvement in the investigation.
Prosecutors in the German city of Cologne said they were also working with the Dutch.
Swiss multinational bank Credit Suisse has become the target of another probe, suspected of helping clients evade taxes. Eighty Swiss banks have entered into non-prosecution agreements with the Department of Justice in return for disclosing details on how tax evasion by their banking clients worked.
It said later it had launched an internal probe.
The Credit Suisse logo is seen at their offices at Canary Wharf financial district in London, Britain, March 3, 2016.
"If any individuals are implicated or have violated against these processes or procedures or policies that are in place then we will identify that very quickly".
"Properties, and jewellery, an expensive auto, expensive paintings and a gold bar from houses in The Hague, Hoofddorp, Zwolle and the municipality of Venlo" were seized, the statement said. The FIOD tweeted a photo of some of the seized assets. Two people were arrested.
Credit Suisse said it is cooperating with authorities and emphasised its "strategy of full client tax compliance". The raids were done without informing authorities in Switzerland, the attorney general's office in that country said in a statement.
"The global reach of this investigation sends a clear message that there is no hiding place for those seeking to evade tax", Her Majesty's Revenue & Customs said in a statement.
Credit Suisse shares fell 1.2 percent, underperforming the wider European banking sector index which rose 0.1 percent on Friday.
To be sure, Switzerland's prosecutor will be of little practical help to Credit Suisse on the ground in France, the Netherlands, the United Kingdom and Australia, where the bank must answer to local, not Swiss jurisdiction.
U.S. regulators fined the bank $2.6 billion (2.4 billion euros) in 2014 for helping Americans evade taxes.
The bank said in December this process had been completed for Europe. "In the next few weeks, more operations will be carried out", the Dutch prosecutors announced.
The bank has been hit hard in the past over tax evasion allegations.
Switzerland began collecting data at the start of the year and will exchange information from 2018. The bank said it has "implemented Dutch and French voluntary tax disclosure programs and exited non-compliant clients", and has applied a withholding tax agreement with the United Kingdom since 2013.
A spokeswoman for the French financial prosecutor's office declined to comment immediately, citing a continuing operation.
The anonymous source also gave the Netherlands information about thousands of suspicious accounts not connected to Dutch clients.
News of probe also comes as Credit Suisse faces hefty criticism in Switzerland as well as by renowned global outlets including "Breaking Views", Germany's "Handelsblatt" (behind paywall), and the "Financial Times" (also behind paywall) for hiking top executive pay.
NYC mayor wants to close Rikers Island jail within a decade
De Blasio credited the drop partly to shifts in how law enforcement handles lower level crimes, like smoking marijuana in public. De Blasio, Lippman and City Council Speaker Melissa Mark-Viverito huddled together at City Hall Thursday night.
Trump to decide whether to stay Paris climate pact by late May
Patton said his company is more interested in the underlying science and economics of climate change than the political rhetoric. But this conflict, this sharpening of the contradiction will energize those who believe climate change is an existential threat.