HSBC, Citigroup, J.P. Morgan, Deutsche Bank, UBS and the inter-dealer broker ICAP are also reported to be under investigation by regulators across the world.
UBS has already secured partial immunity in exchange for co-operation, The Telegraph reported, and Lloyds has already suspended two derivatives traders as part of the investigation.
Yesterday, Barclays was hit with a £60m fine from the FSA and a £230m fine from the US regulator, the Securities and Exchange Commission, as traders were found to have manipulated the inter-bank lending rate LIBOR and EURIBOR.
Barclays, and the other banks, still face fines from other jurisdictions as Japanese, Swiss, Asian and Canadian regulators are also investigating.
The LIBOR investigation began in 2008 as suspicion mounted that the banks were “low-balling” the cost of borrowing as the financial crisis hit. However, it has since been discovered the rates may have been manipulated as far back as 2005.
Barclays yesterday said it “fell well short of standards” and chief executive Bob Diamond and three other senior executives gave up their bonuses for the year.