The ongoing investigation into the accounting scandal at Italian food giant Parmalat has been widened to take in five foreign and two Italian banks.

Placed under investigation were Bank of America, Citigroup, Deutsche Bank, Morgan Stanley, UBS, Banca Popolare di Lodi and Banca Intesa’s fund management unit Nextra, Italian news agency ANSA reported.

They are being investigated on suspicion of participation in market-rigging, it is reported.

Meanwhile Calisto Tanzi, founder and chief shareholder of Parmalat, has been transferred from a Milan jail to prison in Parma so that prosecutors can more easily interrogate him as part of their probe into the accounting scandal.