European fund manager FTC Capital - based in Vienna - has claimed the institutes have colluded to depress the cost of borrowing and to have limited trade between 2006 and 2009 in derivatives linked to the inter-bank lending rate.
In total, 12 banks have been accused - Citigroup, Bank of America, Barclays, Credit Suisse, Deutsche Bank, JP Morgan, HSBC, Lloyds Banking Group, Norinchukin Bank, Royal Bank of Scotland, UBS and West LB.
FTC noted that US dollar Libor rates did not vary significantly during the financial crisis, adding: "In a market not artificially suppressed, Libor rates should have increased significantly during this period."
It explained the banks should have also been receiving very different borrowing rates during this time.
Earlier in the month, the International Monetary Fund warned banks in Europe with regards to funds, noting lenders require greater capital cushions to counter any threats of another monetary crisis.
By Asim Shah