Billionaire Marc Rich lived a double life during his 20 years as a fugitive, funneling secret data to Israeli and other intelligence services about some unsavory governments. Sensational details about Rich's ultimate high-wire act as a spy for Israel and other countries were provided to The Post as congressional committees prepare to hold hearings into former President Bill Clinton's controversial decision to pardon the fugitive commodities trader.

       Among the issues that will be explored by the House Oversight Committee in its probe of the hotly disputed Rich pardon, according to congressional sources, are:Rich's lengthy relationship with the Israeli Mossad. and his numerous contacts with federal prosecutors in New York, during which his lawyers offered to provide intelligence to the CIA in return for leniency. A CIA spokesman denied any relationship with Rich and said no one from the agency participated in behind- the-scenes White House discussions about his pardon.

      But Israeli Prime Minister Ehud Barak repeatedly cited Rich's contributions to Israel's "national security" in phone calls to President Clinton last month in which he lobbied for Rich's pardon, according to Barak spokesman Gadi Baltiansky.  And a letter from former Mossad chief Shabtai Shavit to Clinton confirming that Rich provided "assistance" to the Israeli spy agency that produced results "beyond the expected" was among the documents released last week by Rich's lawyer Jack Quinn to support the Rich pardon.

       "The government of Israel considered Rich a critical ally, and the president took that seriously when he considered the pardon request," former White House spokesman Jake Siewert told The Post. Rich and partner Pincus Green fled the country in 1983 ahead of federal charges that they ripped off taxpayers for $48 million. Both were among the 140 people pardoned or given clemency on Clinton's last day in office.

       A storm of controversy has erupted over the unusual way the Rich pardon was handled, as well as over the involvement of Rich's ex-wife, Denise Rich, who raised $1 million for the Democratic party and gave the Clintons $7,000 in furniture for their new homes. Accounts of Rich's life on the lam - provided by former prosecutors, Rich's lawyers and the Israeli government - sound like a plot from a James Bond movie as the ruthless and nimble Rich extended his empire on five continents and built up a business worth almost $30 billion.

      He sold Iranian oil to Israel and Nigerian oil to South Africa.  He brokered the sale of North Korean arms to Iran and did several deals involving gold, grain, nickel and tin with the Russian Mafia and henchmen of the Soviet Union.

       And it's now clear that Rich also dealt in the most valuable commodity of all - information. He used what one of his former lawyers called a "mammoth information-gathering operation" to gain entree to governments and to support his businesses. "He was one of the biggest commodities traders in the world and had offices and active operations in all sorts of countries. He had friends in all sorts of places - high and low - and he certainly was in a position to provide sensitive information from a number of places," said Martin Auerbach, one of two former assistant U.S. attorneys who prosecuted Rich and tracked him throughout the years.

      Lawyers close to the case say there is no doubt that Rich had contacts with spies and security services throughout Europe and the Middle East. Those contacts not only helped him make money but may have also helped him stay one step ahead of U.S. lawmen trying to capture him, lawyers say.

      Former New York Police Commissioner Howard Safir said he tried several times to trap Rich and bring him back to the United States, when he headed the U.S. Marshals Service, but Rich constantly eluded the federal dragnet.

     Shavit, who headed the Mossad from 1989 to 1996, provided a fascinating glimpse of Rich's role in the murky netherworld of spies. In his letter to Clinton released by Quinn's office, Shavit said that he had a long relationship with Rich. "We requested his assistance in looking for MIAs and his help in the rescue and evacuation of Jews from enemy countries," Shavit wrote. "Mr. Rich always agreed and used his extensive network of contacts in these countries to produce results that sometimes were beyond the expected."  Murkier still were Rich's efforts to become a superspy for the CIA.

      During his intrigue-filled exile, Rich's lawyers made numerous approaches to government prosecutors, offering intelligence to the CIA about the terrorists and rogue governments he dealt with in return for being allowed to return to the United States without being subjected to a jail sentence. "Whether or not he provided the information, it never rose to a level where it justified any sort of leniency," Auerbach said.

     Asked whether security and intelligence considerations involving the United States played any role in the Rich pardon, a former Clinton aide said, "I simply don't know."