Nevada Sen. Harry Reid contributed $500 last spring to the legal defense fund of fellow Democratic Sen. Robert Torricelli, who was fighting a criminal investigation into his finances.

Now Torricelli's fate is in the hands of Reid and five other members of the Senate Ethics Committee, which has the awkward task of passing judgment on colleagues.

Charles Lewis, executive director of the Center for Public Integrity, a government watchdog group, said Reid's donation is an example of why a "clubby" institution like Congress should not be trusted policing itself.

But Nathan Naylor, a spokesman for Reid, said the donation to Torricelli's defense fund was nothing unusual. "They've been friends and colleagues for years, and Senator Reid has always supported his friends," Naylor said.

He said Reid has a policy of not commenting specifically on any case before the ethics committee, which Reid chairs.

The U.S. attorney in Manhattan, Mary Jo White, closed a three-year criminal investigation Thursday without filing charges against Torricelli. But she said she had sent information on the New Jersey senator to the ethics committee.

Torricelli said the referral was a routine act by the prosecutor, and he expressed confidence the committee will not act.

The committee, created in 1964, investigates alleged violations of law or Senate rules, plus any other conduct that reflects poorly upon the Senate.

It has the power to recommend disciplinary action to the full Senate, but only by a majority vote. Because the committee has an equal number of Democrats and Republicans, disciplinary action requires the vote of at least one member of the accused lawmaker's own party.

The committee considers almost any complaint it receives, but few cases result in public action against a member.

Some have, however:

--Sen. Bob Packwood, R-Ore., resigned in 1995 after the committee recommended his expulsion for, among other things, making uninvited advances toward female employees and colleagues.

--The Senate, acting on a recommendation from the committee, in 1990 denounced Sen. David Durenberger, R-Minn., for financial misconduct involving book and real estate deals. He was ordered to pay more than $124,000 in restitution.

The committee's procedure is to open a preliminary inquiry into any allegation it receives. The full committee then votes whether there is "substantial credible evidence" that a violation occurred.

It can dismiss the case, issue a public or private letter of admonition in cases of inadvertent or technical violations, or continue with a full investigation.

The committee also can, by a unanimous vote, order that a member be reprimanded or pay restitution, or both.

Besides Reid, the Democrats on the committee are Sens. Daniel Akaka of Hawaii and Blanche Lincoln of Arkansas. The Republican members are Sens. Pat Roberts of Kansas, George Voinovich of Ohio and Craig Thomas of Wyoming.

The nature of the material White submitted is not known. But one central topic of the criminal investigation -- alleged gifts to Torricelli from a New Jersey businessman and political donor, David Chang -- is familiar territory to the ethics committee.

The committee oversees the Senate's tight restrictions on gifts and the annual financial disclosure process, during which lawmakers must reveal sources of income and gifts.

Torricelli has maintained he took no illegal gifts and calls Chang a liar. Chang is awaiting sentencing for making illegal campaign donations to Torricelli's 1996 campaign.