"Multiple traders" in New York and possibly elsewhere in "the Americas" are affected after investigations into "communications across a number of currencies," the source said.
German daily Die Welt, citing people familiar with the investigations, said on Wednesday one trader in New York who traded Argentine pesos had been suspended.
According to Die Welt sources at the bank, emails were found that led to suspicion that rates had possibly been manipulated, the paper said in a story published in its Wednesday edition.
Deutsche Bank said it would not comment on individual staff members.
"Deutsche Bank has received requests for information from regulatory authorities that are investigating trading in the foreign exchange market. The Bank is cooperating with those investigations, and will take disciplinary action with regards to individuals if merited," it said in a statement.
(Reporting by Jamie McGeever)