Citing sources, 'The Financial Times' said "evidence of links between traders at all four banks and Barclays' former euroswaps trader Philippe Moryoussef is under scrutiny."
The news comes in the wake of the resignation of Barclays Chairman Marcus Agius earlier this month following the bank being slapped with 290 million pound fine by the US and the UK authorities to settle charges of manipulating global benchmark lending rates.
The US futures regulator Commodity Futures Trading Commission, had recently described an unnamed trader as having "orchestrated an effort to align trading strategies among traders at multiple banks in order to profit from their futures trading positions