THE JEAN SEBERG story burst into the news just a year ago. It was awful. Miss Seberg, an actress, had died in Paris from an apparent overdose of barbiturates. Her former husband, the author Romain Gary, had charged the Federal Bureau of Investigation with having driven her into the state of emotional instability that led to her death.

Back in 1970, or so the story went, the FBI had planted false rumors that Miss Seberg was pregnant with the child of a Black Panther leader to whom she was not married. Mr. Gary was quoted as saying that when Miss Seberg saw this gossip in print, she was so shocked she went into premature labor and gave birth to a dead child. She never recovered from that experience, Mr. Gary said, and she tried to commit suicide every year on the anniversary of the stillbirth.

A week after this story hit the television screens, the FBI released a set of documents concerning the incident. Letting the documents speak for what the FBI had done, Director William Webster issued a statement saying, "The days when the FBI used derogatory information to combat advocates of unpopular causes have long since passed. We are out of that business forever."

This sequence of events produced a wire service report, published in this and many other newspapers, that the FBI had "admitted" it spread the "gossip" in question. That, in turn, provoked a new wave of denunciation of the FBI, almost all of it based on the premise that the FBI had circulated a false story that seriously damaged Miss Seberg. We referred to the matter on this page as an example of the way in which J. Edgar Hoover had used his power "to harass and persecute citizens charged with no crime."

Well, a batch of documents now being circulated by Accuracy in Media makes clear it wasn't quite that way. Looked at closely, those documents, available last September, show that the FBI didn't "admit" that it had leaked that story; they indicate the FBI doesn't know who leaked it. Other documents made available since September, transcripts of wiretaps, make it reasonably clear that the story about who impregnated Miss Seberg was true, that she was having trouble carrying the child before that news was published and that she wasn't nearly so distressed by its publication as Mr. Gary claimed.

So the truth appears to be that the Los Angeles office of the FBI recommended that accurate news of Miss Seberg's pregnancy be planted in gossip columns to sow dissension among the Black Panthers with whom she was involved. Headquarters in Washington thought the idea was a good one but told Los Angeles to wait for two months. The idea was later dropped, according to the FBI files, because of a decision that it would cause no dissension.

In the meantime, the story had been published by a Los Angeles columnist. It was later published by Newsweek. Both authors deny they got their information from the FBI, and the agents in charge of the matter deny they were the source.

What difference does it make, now that the child, Miss Seberg and the COINTELPRO operation of the FBI, which plotted to harm her, are all dead? Just this: the news media gave the FBI a black eye for the wrong reasons. When the invalidity of those reasons is exposed, there is a danger that justified as well as the unjustified criticism will be ignored.

As Director Webster well understands, the FBI had no business considering a plan to harm Miss Seberg by leaking personal information, true or false. The fact such a plan was recommended and approved, even if never executed, was plenty bad enough -- another demonstration of the arrogant and abusive way the old FBI viewed its power and license. That's where the Jean Seberg story -- and the commentaries based on it -- should have stopped. It was unfair and inaccurate -- not to mention totally unnecessary for the purpose of showing the evil of the COINTELPRO operation.