Italian tax police visited the offices of ratings agency Fitch in Milan on Tuesday to carry out checks ordered by prosecutors investigating rival agencies Standard & Poor's and Moody's, a senior prosecutor told Reuters.

Men from the financial police are at Fitch in Milan, said Carlo Maria Capristo, chief prosecutor in Trani, without giving more details.

The Trani prosecutors are investigating possible crimes of market manipulation and illicit use of privileged information when Standard & Poor's downgraded Italy earlier this month.

As part of the same probe, they are also investigating the impact reports by Standard & Poor's and Moody's on Italy and its banking system had on markets and whether any crimes were committed.

It was not immediately clear whether the probe had been extended to Fitch, which put Italy and five other euro zone states on negative watch in December and said it could downgrade Italy by two notches by the end of January.

There was no immediate comment from Fitch.

Financial police had already searched S&P's offices in Milan on January 19.

S&P said then it had nothing to add to a previous statement in which it said it believed the probe was groundless. Moody's has said it takes the dissemination of market sensitive information very seriously and is cooperating with authorities.

The probe in Trani, a small town in southern Italy, was opened after a complaint by two consumer groups over the impact of reports about Italy by the rating agencies on Milan stock prices.

The consumer groups have said they had first contacted prosecutors in Milan and Rome but had been turned down.

Judicial sources said the Milan's chief prosecutor, who on Monday put out a statement to say his office was not investigating S&P in relation to its ratings assessments, believed there were not enough elements to launch a probe.

(Reporting by Sara Rossi)