Like most Americans, I was disgusted by the Abscam videotapes that showed members of Congress taking bribes from a fake Arab sheik. And like most Americans, I thought the FBI had done a brilliant job exposing the venal frailty of our lawmakers.

But now I'm having serious doubts that the game was worth the candle. Evidence has come to light indicating that the Fbi violated the law to set its Abscam traps and then misled Congress about the extent of the bureau's lawlessness.

The appeals court will decide whether the FBIs conduct violated the "due process" rights of those convicted and invalidated the entire Abscam prosecution. If the convictions are thrown out because of entrapment or other illegal FBI activity, the price will be far greater than the expense of the investigation and trials.

My associate Indy Badhwar had dug into court documents and Justice Department files for evidence of the FBI's activities. Here's what he found:

FBI agents created illegal banks and opened fictitious accounts in legitimate banks. This violated banking laws designed to prevent manipulation of financial institutions by government officials using the taxpayers' money.

By setting up its own corporation, the FBI not only underbid private companies for government contracts, but also raised money for its own use instead of getting it from Congress -- a clear breach of the law intended to maintain congressional control over government spending.

The FBI may have condoned the forgery of an incriminating letter to snare a targeted senator.

The FBI supervisors of the prosecution's star witness, convicted con man Mel Weinbert, may have covered up accusations that he had ripped off Abscam targets for gifts, and had instigated the forgery of nearly $2 billion in counterfeit securities. In fact, the FBI awarded Weinberg a $15,000 bonus for "recovering" the fake securities.

On the last point, it is important to remember that the accusations of Weinberg's misconduct came not only from potential defendants who dealt directly with him, but also from two Justice Departrment attorneys, Edward Plaza and Robert Weir. In an internal memo to their superiors, Plaza and Weir accused Wemberg of using Abscam for his own profit and of coaching investigation targets and putting words in their mouths -- despite the attorney's warnings that that could endanger the entire prosecution. Instead of doing anything about Weinberg, the Justice Department replaced Plaza and Weir as Abscam supervisors. The FBI's director, William Webster, subsequently persuaded Congress to legalize the kind of activities the bureau had engaged in by "remedial legislation" that Congress barely understood. Certainly the lawmakers didn't understand that the FBI had already been carrying on the questionable operations they were being asked to approve and that some of its own members were the targets.

And what were the FBI's motives? Consider this: while Abscam was being planned, the new FBI charter was being debated in Congress. There was a possibility that Congress -- in light of the FBI's past abuses -- would curtail the agency's powers. But Abscam came along to capture the public's imagination and to intimidate Congress into the consideration of a more favorable FBI charter.

The basic question of Abscam's validity remains: Would any crimes have been committed without the FBIs instigation? In an Orwellian pre-emptive strike at the entrapment argument, the FBI dubbed Abscam a "proactive" operation, to distinguish it from a "reactive" operation where criminal activity has already been detected.

To justify a "proactive" operation where no crime had yet been committed, the FBI said; it selected as targets members of Congress the bureau decided had a "criminal predisposition." Then it made its prophecy self-fulfilling by inducing the legislators to commit government designed crimes.

Just who bestowed such psychological omniscience on the FBI is not clear, but the potential for mischief in this kind of "voodoo law enforcement" is frightening.