Germany's biggest bank, Deutsche Bank, prepared the ground for regulatory action in the Libor rigging scandal by admitting that a "limited number" of its staff had been involved.

As Swiss bank UBS insisted it was not at the centre of the interest rate debacle, Deutsche said "action had been taken accordingly" against those staff found to have been involved. UBS, as the first bank to reveal the existence of investigations into Libor, is receiving leniency for co-operating with inquiries.

Deutsche's supervisory board head Paul Achleitner insisted in a letter to staff that "no current or former member of the management board had any inappropriate involvement".

Deutsche's admission follows a warning by Royal Bank of Scotland that it too expects to be drawn into the Libor debacle in the wake of the £290m fine slapped on Barclays. Barclays refused to comment on reports that its offices in Milan had been raided in connection with the investigations.

Deutsche's new co-chief executive Anshu Jain used to run the investment banking operations of the bank, but the internal probe has cleared him of any involvement. Jain yesterday announced plans to cut 1,900 jobs – largely outside Germany – and clean up the culture of banking. Bonuses are to come down and codes of "personal conduct" are being reviewed.