PALERMO, Sicily (AP) _ With help from Italy's crumbled political dynasty, prosecutors on Thursday peered further into a Mafia they allege once enjoyed the friendship of Italy's most powerful party and its venerated leader.

The charges by one-time allies of former Premier Giulio Andreotti have drastically reshaped the investigation of alleged ties between the Sicilian Mafia and the 76-year-old Andreotti, who was premier seven times in 1972-92.

The case up to now had been built around the claims of Mafia turncoats, whom Andreotti dismissed as liars and killers. But the new wave of testimony by members of his disgraced Christian Democrat party have added depth and credibility to the allegations, prosecutors say.

Andreotti's attorneys asked to postpone a Friday court appearance so they can examine more than 1,400 pages of statements from former political figures. The hearing will help a judge decide whether Andreotti should be indicted.

It was the second time in a month that new evidence forced his lawyers to move for a delay.

If Andreotti is indicted, he would become the most senior Italian political figure dragged into court on Mafia charges. Other former premiers have been implicated in the nation's 3-year-old anti-corruption housecleaning that has touched more than 3,000 business and political figures.

This week, prosecutors began mining a motherlode of new claims by former Christian Democrat members. They claim the Mafia infiltrated every level of the party, which dominated Italian politics from World War II until it was destroyed by corruption scandals last year.

Andreotti, they claim, developed close bonds with some mob bosses, and one mobster called him ``Uncle Giulio.''

The first and so far most comprehensive claims came from Gioacchino Pennino, a former Christian Democrat city councilman in Palermo. Prosecutors said Pennino sketched out the alleged links between Andreotti and Mafia clans.

Pennino claimed the mediator was Salvo Lima, a European parliament member who was assassinated in 1992 and who was considered Andreotti's top party man in Sicily.

One of the party's former senators, Vincenzo Inzerillo, was taken into custody on Wednesday and reportedly corroborated some of Pennino's claims.

A former Christian Democrat Cabinet member, Calogero Mannino, was arrested earlier this week on mafia charges and was questioned Thursday.

Prosecutors had already built a hefty file based on the testimony of Mafia turncoats. Some of the interrogations were done in the United States, where at least two ex-mob collaborators are living under government protection.

One of the turncoats in Italy, Balduccio Di Maggio, claims he witnessed a meeting in 1987 between Andreotti and Mafia kingpin Salvatore ``Toto'' Riina. The two men exchanged the traditional kiss of respect on both cheeks, said Di Maggio, who was Riina's driver.

Riina was arrested in January 1993 and has been implicated in several notorious attacks, including the 1992 highway bombing outside Palermo that killed anti-Mafia crusader Judge Giovanni Falcone. Four other people suspected of being Mafia members were indicted Thursday, which could postpone the start of Riina's trial scheduled for next week.

Andreotti has initiated a media blitz to counter the charges and try to save his reputation.

With practiced calm, he asserts his innocence and tries to depict the mob turncoats as opportunists seeking revenge for his efforts to stamp out the mob.

``What will they find? Nothing,'' he said. ``They have investigated me and still have found nothing but unsubstantiated claims.''