Banca Monte Paschi di Siena prosecutors wil seize billions of euros worth of Nomura assets as part of an investigation into the world's oldest bank use of derivatives to hide losses and possible mis-selling by the Japanese firm.

In a statement read out in Italian court and cited by various news organisations, prosecutors in Siena, Italy are seizing €1.8bn (£1.5bn / $2.3bn) from Nomura and have already acquired €14.4m of assets from former Monte Paschi chairman Giuseppe Mussari, ex-managing director Antonio Vigni and the former head of the finance department Gian Luca Baldassari.

Prosecutors said in the statement that the Nomura seizure related to €88m worth of hidden commissions and €1.7bn euros of funds deposited with the Japanese bank by Monte Paschi by way of collateral for a loan.

Monte Paschi declined to comment and Nomura were unable to provide a statement at the time of this article's publication.

In February, Monte Paschi received a €4bn state bailout to boost its ailing capital base, after it lost €730m from its net assets in a string of derivatives trades.

One month later, Italy's tax police searched the Milan offices of Nomura as part of a judicial probe into the Italian lender. It had already carried out the same procedure at Monte Paschi's premises in Siena as part of an investigation into suspected insider trading.

In tandem, Monte Paschi revealed recently that it was seeking €1.2bn in damages from two former employees, as well as Deutsche Bank and Nomura, after it suffered huge losses from a number of structured finance deals.

The group also said in a statement that the bank's board had started liability actions and claims for damages against former chairman Mussari and former general manager Vigni, along with Nomura and Deutsche Bank, over the two most costliest trades. The amount of damages claimed was not specified.

The bank said it had started corporate liability action in the civil court in Florence against Mussari and Vigni and an extra-contractual liability action against Nomura regarding the financial restructuring transaction, known as Alexandria, carried out between July and October 2009.

It added that it had also started corporate liability action against Vigni and an extra-contractual liability action against Deutsche Bank over total return swap transactions carried out through the special purpose vehicle, Santorini Investment.