The Federal Court has approved the handover to Italy of more bank documents linked to a probe into the Mediaset empire of former prime minister Silvio Berlusconi.
The Federal Prosecutor's Office, which announced the ruling on Friday, said the judges in Lausanne had rejected appeals from Berlusconi's lawyers against the Swiss decision to cooperate with the Italian investigation.
At issue were documents concerning bank accounts frozen in Switzerland since October 2005 containing more than SFr150 million ($136.16 million). Other bank files have already been provided to the Milan prosecutor's office, which has been leading the investigation.
Switzerland has received more than 20 requests from Italian authorities for assistance in their probe linked to Berlusconi.
Switzerland's highest court has rejected a whole series of appeals to block the assistance, and the Swiss prosecutor's office has opened its own investigation into whether money laundering was involved.
The Milan prosecutors have been investigating alleged fictitious and elevated payments for film and television rights by Mediaset, which is controlled by Berlusconi's family through its Fininvest holding company.
Italian prosecutors say Mediaset, Italy's private broadcaster, purchased TV rights for United States films before 1999 through two offshore companies and falsely declared the costs to reduce the tax bill.
Berlusconi, who has been Italian prime minister twice, has a history of legal troubles linked to his Milan-based business interests. However, he has either been acquitted or seen cases against him dismissed because the statute of limitations had expired.
He has repeatedly maintained his innocence and on Thursday denied that he had manipulated Italian television when he was prime minister, saying he was victim of a smear campaign.
The issue of whether Berlusconi controlled TV in his five years in office resurfaced with a newspaper report that Mediaset and state-owned RAI colluded to give him favourable news coverage.
"Ever since I've been in politics I am someone who has taken away [certain people's] powers... I'm the enemy," he told reporters.
He was referring to the leftwing daily La Repubblica which printed transcripts of what it said were telephone calls between RAI and Mediaset executives recorded by police probing a separate matter.
Communications Minister Paolo Gentiloni of the centre-left government that took over after a narrow victory in the 2006 elections, said the transcripts prove what the Left had always assumed – that Berlusconi had controlled almost all Italian TV.
"Sometimes urban myths are more than that... sometimes they're actually true," he said.
Mediaset chief executive Fedele Confalonieri countered that the phone conversations were entirely normal. He argued it was no coincidence the affair had emerged in the same week that Berlusconi announced his strategy for a political comeback by forming a new party.
swissinfo with agencies
The Swiss Public Presecutor's Office in Bern received between 2002 and 2006 more than 20 requests from Italy for assistance linked to their investigations concerning Berlusconi.
Several dozen appeals were made against granting assistance, which were all rejected by the Federal Court.
The accounts in Switzerland containing more than SFr150 million remain frozen.
Fininvest is a financial holding company controlled by Silvio Berlusconi's family.
The group is composed of Mediolanum (insurance and banking), Medusa (film production), Mondadori (publishing), AC Milan (football) and Mediaset, which is, at present, the biggest private broadcaster in Italy.
Mediaset owns three channels (Canale 5, Italia 1 Rete 4), a digital television network and other companies related to broadcasting.