Standard & Poor's, the US rating agency, yesterday became the latest international financial institution to receive a visit from Italian police as Parmalat prosecutors cast wider for evidence into who knew what about the true state of the food giant's finances before its spectacular collapse.

S&P stressed that magistrates had told the ratings agency that it was not under official investigation, adding that the company "obviously welcomed" the chance to co-operate with magistrates. A London-based spokeswoman reiterated that S&P had been the victim of an "apparently massive fraud" by Parmalat's former managers, based on "detailed, false information" she claimed they had supplied the agency.

S&P kept an investment grade rating for the bankrupt food multinational's debt until December, when the apparent fraud at Parmalat exploded into the open. "The information on which we based the ratings was totally untrue," the spokeswoman said.

The police search of S&P's Milan offices came a day after magistrates also seized documents from Morgan Stanley, the US investment bank, and Nextra, the fund management arm of Banca Intesa, Italy's biggest bank.