In addition to impounding the assets of the Milan branch of Japan’s Nomura International, the Italian police has also seized assets from three former executives of Monte dei Paschi.

The seizures include €2.3m from ex-MPS executive chairman Giuseppe Mussari, €9.9m from former general manager Antonio Vigni and €2.2m from ex-executive Gianluca Baldassarri.

Nomura Europe former chief executive Sadeq Sayeed along with Raffaele Ricci, an executive at the bank, is also placed under investigation, for their alleged roles in hindering judicial investigations and violation of market rules.

The case is part of a structured-products transaction, known as Alexandria, which was carried out in 2009 under the former management of Monte dei Paschi with Nomura.

Monte dei Paschi, which was given an emergency €4bn government loan this year, alleged that inaccurate representations in its accounts related to the transaction by its former executives led to €273.5m losses to the Italian lender.

In response to the development, Nomura said that it was aware of the statement issued by Siena prosecutors regarding the potential seizure of collateral in relation to trades with Monte dei Paschi.

"We will take all appropriate steps to protect our position and will vigorously contest any suggestions of wrongdoing in this matter," the bank added.