Silvio Berlusconi's government has admitted that agents of Sismi, the Italian military intelligence service, tracked the movements in London of Rocco Martino, an ex-informer, in the autumn of 2001. It did not say whether the British authorities were informed, but admitted that Mr Martino was also followed by Sismi in the US, without the knowledge of the FBI.
According to Italian press reports, however, Mr Martino had a meeting with the Secret Intelligence Service in London. A year later, the 66-year-old, who made a living peddling information to intelligence services and journalists, was the source of forged documents purporting to show that Saddam Hussein was buying uranium for nuclear weapons from the west African state of Niger.
The documents were used by the US to make its case for war. President George Bush cited the uranium claim in his State of the Union address in January 2003. But as soon as the US passed the documents to the UN's nuclear watchdog, the IAEA, it denounced them as obvious fakes. The ensuing controversy in America has now resulted in charges against a top former White House official, Lewis "Scooter" Libby, and a continuing investigation into Karl Rove, Mr Bush's closest aide.
But while the US has admitted the uranium claim should never have been made, Tony Blair's government, which first made the allegation public in its September 2002 dossier on Iraq's alleged weapons of mass destruction, still insists it was supported by "separate intelligence".
Britain has always refused to disclose the nature of this information, even to the IAEA, because it was provided by a "foreign service".
In October 2001, Sismi sent its British and American counterparts a dossier on alleged Iraqi attempts to buy uranium from Niger. Whether Rocco Martino delivered it to MI6 headquarters in Vauxhall Cross, as some Italian reports claim, is not clear.
But Vincent Cannistraro, a senior former official with the CIA, told The Independent on Sunday that "some of the text of the 2001 report showed up in the later [forged] documents.
"There seems to be a common source ... it seems that the [separate] British intelligence came from the same false and discredited source."
A public row in Italy involving the head of Sismi, General Nicolo Pollari, has brought to light much information on the Niger uranium claims. Sismi has acknowledged informing other intelligence services, including the CIA, in a letter on 15 October 2001, of "evidence of intelligence" on Iraqi efforts to procure uranium from Niger.
The information came from a woman who worked at the Niger embassy in Rome, given the code name of La Signora by Sismi. She also provided Niger's cryptographic codes and other internal documents.
The CIA questioned the report, and General Pollari says he also recorded his doubts in writing at the time. But he does not appear to have told his counterparts in other countries, where La Signora was still "a reliable source".
Sismi says it was next involved in 2002, when Mr Martino began offering the fake Niger documents to anyone willing to buy them. His first client is reported to have been the French intelligence service, but in October 2002 they were given to the American embassy in Rome by Panorama, a Berlusconi-owned magazine he had approached.
What happened next is the subject of furious argument in Italy. General Pollari says he warned other countries about the forgeries, including Britain.
In spring 2003, according to his account, Mr Martino approached the British embassy in Brussels, saying an "associate" could provide information on Iraq, Niger and uranium. The British asked Sismi to identify the man from CCTV images, and the Italians asked them to string him along in order to uncover the associate. Eventually Mr Martino admitted there was no one else involved.
The Sismi chief identified Mr Martino as the source of the forged documents in a closed Italian parliamentary committee meeting last week. He described Mr Martino as a former intelligence informer who had been "kicked out of the agency". Both men have claimed that at the time he was hawking around the documents, Mr Martino was working for the French, a possible source of Britain's "separate intelligence". A senior French intelligence official declined to say whether Mr Martino had been a paid agent of France, The New York Times reported last week, but called General Pollari's assertions that France disseminated the false documents "scandalous".
General Pollari's critics in Italy claim he worked closely with American neo-conservatives to spread the Niger uranium claims to the highest levels of the US administration, bypassing the CIA. He is said to have had a meeting in Rome in December 2001 with a group of neo-cons led by Michael Ledeen, an influential hawk close to Israel and involved in the Iran-Contra scandal in the 1980s.
The same critics see Mr Martino as a useful pawn. In an Italian newspaper yesterday, he repeated that he had not forged the documents nor known them to be forged. He is unlikely tohave imagined their impact.
Revelations in Italy support the Butler inquiry's statement that British intelligence had not seen the forged documents when Mr Blair's WMD dossier was published in September 2002. But the inquiry's conclusion that Britain's "separate intelligence" was "credible" has been widely criticised.