U.S. and EU prosecutors are on the verge of arresting traders connected with the Libor rate fixing scandal, it emerged on Monday.

According to a number of un-named sources that are familiar with a sweeping investigation into the rigging scandal cited by Reuters, federal prosecutors in Washington have recently contacted lawyers representing some of the suspects to notify them that criminal charges and arrests could be imminent.

The individual criminal charges have no impact on the regulatory moves against the banks but banks are hoping that at least regulators will see that the scandal was mainly due to individual misbehavior of a gang of traders.

More than a handful of traders at different banks are involved, said an un-named European source familiar with the matter, cited by Reuters.

News of the 'imminent' arrests follow reports that traders from at least five major banks are currently under investigation.

Philippe Moryoussef has left his derivatives trading post in Singapore with Nomura, as he is also under investigation for the time he period he spent working for Barclays, which was between 2005 to 2007.

In a statement, a spokesman for Nomura said: Nomura is aware of the investigation into the setting of Euribor and Libor rates.

The allegations against Mr Moryoussef are related to a period of time before he joined Nomura. We would point out that Nomura is not a member of either the Euribor panel or the Libor panel, and therefore has no role in the setting of those rates.

According to reports, regulators are also said to be investigating Michael Zrihen at Credit Agricole, Didier Sander at HSBC  -- who according to the Telegraph exchanged emails with Barclays' Moryoussef -- and Christian Bittar at Deutsche Bank.

None of the executives currently work at the banks.

HSBC is not formally tied to the Libor scandal, with an  Financial Services Authority spokesman telling the Telegraph the bank was not currently under investigation.