Germany's Deutsche Bank has said police are searching a number of its offices.

The investigation has to do with the Panama Papers case.

The papers were some 11.5 million files, relating to thousands of off-shore companies, which were leaked from the Panama-based law firm Mossack Fonseca in 2016.

Deutsche Bank said their head office at Taunusanlage in Frankfurt and other bank premises are being searched.

Police and the public prosecutor's office arrived on Thursday morning.

Civilian police investigators enter Deutsche Bank's headquarters in Frankfurt | Image: Boris Roessler/dpa

The investigation is centered around allegations that some staff helped customers set up offshore companies in tax havens and launder money from criminal activities.

In a statement, Deutsche Bank said: "As far as we are concerned, we have already provided the authorities with all the relevant information regarding Panama Papers.

"Of course, we will cooperate closely with the public prosecutor's office in Frankfurt, as it is in our interest as well to clarify the facts."

Illuminated view of Deutsche Bank headquarters in Frankfurt | Image: Frank Rumpenhorst/dpa

The bank added that it has proven "that we fully cooperate with the authorities - and we will continue to do so."

Deutsche Bank employs around 100,000 staff in more than 70 countries worldwide.

It has had a presence in Ireland since 1991, and employs over 650 people in Dublin.

Deutsche Bank's Dublin office declined to comment.