Italian police have seized documents at the Milan offices of Barclays as part of an investigation into bank-to-bank lending rates.
The search last week was ordered by prosecutors in the southern city of Trani who launched a criminal probe into possible manipulation at Euribor after complaints from two consumer groups.
Euribor is the euro-priced counterpart of scandal-hit Libor.
In a statement, Abusbef and Federconsumatori said documents, computer material and emails were seized at Barclays' Milan offices "with the aim of looking for evidence that Barclays also manipulated Euribor, as it did with Libor, with a negative impact on mortgage rates paid by Italians."
Barclays was not available for comment.