* Case involves suspicion of money laundering
* Still ongoing
* Deutsche Bank said it is cooperating (Updates with further details, background)
FRANKFURT, Sept 25 (Reuters) - German authorities have raided Deutsche Bank's Frankfurt headquarters and are searching for information related to Danske Bank and a money laundering scandal, Frankfurt prosecutors said on Wednesday.
They are investigating whether Germany's biggest bank facilitated money laundering and whether it failed to alert authorities about suspicious transactions quickly enough, the prosecutors said.
Danske Bank is under investigation in several countries, including the United States, Denmark, Britain and Estonia, over suspicious payments totalling 200 billion euros ($220 billion) moved through its tiny Estonian branch. Deutsche Bank acted as a correspondent bank for Danske.
The search, which began on Tuesday and is still ongoing, involves three prosecutors and nine agents from Germany's federal criminal police. The prosecutor's office said it was not clear how long the action would continue.
Deutsche Bank said it was cooperating. "Deutsche Bank has comprehensively examined the facts of the matter and has voluntarily provided the requested documents as far as possible," the bank said in a statement.
Prosecutors said the period in question is 2014 to 2018, and that there was a suspect who worked at the bank during that period.
Deutsche Bank had alerted authorities to 1.1 million suspicious transactions, prosecutors said.
Prosecutors also said that a double-digit number of transactions, with a volume of 12.5 million euros, were either registered by Deutsche too late with authorities, or the bank should have blocked them from the start.
Deutsche Bank has previously faced issues over money laundering and the controls in place to prevent it.
Last year, dozens of police raided six Deutsche Bank offices in and around Frankfurt over money laundering allegations linked to the "Panama Papers."
Germany's financial market watchdog BaFin last year ordered Deutsche to do more to prevent money laundering.
In 2017, Deutsche Bank was fined nearly $700 million for artificial trades between Moscow, London and New York that could have been used for money laundering. An investigation by the U.S. Department of Justice is still ongoing. (Reporting by Hans Seidenstuecker, Patricia Uhlig and Tom Sims; editing by Thomas Seythal and Alexandra Hudson)