The FBI violated a court order prohibiting terrorism probes of legitimate domestic groups when it investigated a group of Americans opposed to U.S. policy in Central America, a federal magistrate has decided.

U.S. Magistrate Joan H. Lefkow in Chicago recommended that the Federal Bureau of Investigation be ordered to destroy its records on the Chicago Committee in Solidarity with the People of El Salvador (CISPES), and pay CISPES's legal costs.

Lefkow's findings, presented to a federal judge this week for final judgment, are the latest fallout from the FBI's probe of CISPES in 1983-85. In 1989, the Senate Select Committee on Intelligence termed the CISPES investigation a "serious failure in FBI management" that violated the rights of hundreds of Americans opposed to Reagan administration policies in Central America.

An internal FBI investigation led to disciplinary action against six FBI supervisors involved in the probe. FBI Director William S. Sessions also ordered that procedures for authorizing and conducting counterterrorism investigations be tightened.

Lefkow rejected the FBI's argument that its procedural changes made the case moot. "Although the FBI has enacted new guidelines, they have also enacted guidelines in the past which were meant to prevent this type of investigation," Lefkow wrote.

"Based on the FBI's past behavior, there is a reasonable likelihood of repetition."

The CISPES terrorism probe began in 1983 when a Salvadoran alleged to the FBI that group members were taking orders from and sending military assistance to Salvadoran guerrillas and planning terrorist acts. The initial allegations triggered 178 spinoff investigations.

Lefkow's 36-page report said the FBI used infiltrators, undercover agents and photographic surveillance to investigate CISPES members. Agents also obtained bank and telephone records, the report said.

The Justice Department ordered the CISPES case closed in 1985 for lack of evidence, but the FBI office in Chicago continued to collect information, according to the magistrate.

Lefkow said the FBI's actions violated a 1981 consent decree in a Chicago case brought by civil liberties groups, in which the FBI agreed that it would not investigate activities protected by the First Amendment.

Richard Gutman, a CISPES attorney, said he hopes Lefkow's findings will deter the FBI from its current program to interview Arab Americans for information about terrorism. FBI spokesman Thomas Jones had no comment.