The activist who successfully lobbied the White House for the release of 14 jailed Puerto Rican separatists was a leader in the terrorist organization FALN, a congressional report alleges.

The report said that Luis Nieves Falcon, who corresponded with several top Clinton administration officials on the clemency, was a member and leader of the militant Puerto Rican independence group.

The report, prepared by the Committee on Government Reform, included letters documenting Falcon's correspondence and at least one meeting with the Clinton administration. It cited federal law enforcement sources who had requested anonymity in declaring him a leader of the terrorist group.

Falcon did not immediately return phone calls.

FALN--the Spanish initials for the Armed Forces of National Liberation--was responsible for a wave of bombings in the late 1970s and early 1980s that left six dead and dozens wounded.

Rep. Dan Burton (R-Ind.), who heads the committee, blasted the Clinton administration for negotiating with a terrorist.

"The fact that the White House and the Department of Justice were negotiating with a terrorist leader, and working with him as partner to achieve the goal of letting the terrorists out of prison is unconscionable," Burton wrote.

Jim Kennedy, of the White House Counsel's Office, said Falcon was one of the leading advocates for the prisoners' release but was not involved in negotiations. "The notion that the White House negotiated with a terrorist is pure partisan fantasy," Kennedy said.

Kennedy would not comment on whether Falcon was a terrorist.

Subpoenas issued by Burton's committee turned up letters to Falcon from seven high-ranking Clinton administration officials, including then-White House Counsel Bernard Nussbaum and White House Deputy Chief of Staff Maria Echaveste. Most were routine letters acknowledging the receipt of information and letters that Falcon had sent on the prisoners' behalf. Others answered Falcon's questions about the transfer of prisoners and other inquiries.

But Burton said the frequent correspondence with Falcon was an "insult to the victims" of FALN bombings who have testified at recent Capitol Hill hearings that the administration did not answer their letters.

The documents indicate that Falcon met at least once with a Justice Department official. And they suggest he was scheduled to attend a White House meeting in December 1996 on the clemency, though it was unclear if he did.

Administration officials said Falcon had been inside the White House in March 1996 with several lawmakers and advocates to deliver letters of support for the prisoners' release. They said yesterday that they were unaware of any other visits and said he had never met with the president.