Citigroup on Monday stepped up its fight back against Enrico Bondi, Parmalat's administrator, going public with a set of arguments made in an Italian court filing seeking to affirm its innocence in the spectacular collapse of the Italian dairy company.

After a long period of discretion, the gloves are truly off in the battle between Mr Bondi, who is trying to resurrect the company after its collapse amid fraud, and the banks and auditors being targeted by the administrator, investors and regulators.