Politico’s story on possible sexual harassment by Herman Cain may be the biggest investigative scoop of the campaign season. But it would be hard to deduce that from the facts as published.

The story lacks the key details needed to judge whether the allegations amount to a fatal character flaw in a candidate suddenly running near the top of the polls. For example, the story quotes unnamed sources as saying the National Restaurant Association paid two settlements in the “five-figure range” to deal with charges of harassment by Cain, who was president and CEO of the trade group from 1996 to 1999.

Were the settlements $99,999 each (to borrow some of Cain’s favorite numbers)? Or a buck more than $9,999?

The former would suggest, but not prove, that something seriously untoward had occurred. The latter would sound like what lawyers term nuisance settlements – the money corporations routinely shell out to make frivolous claims go away.

After providing equivocal denials to Politico, Cain came out swinging yesterday. “In all of my 40 years of business experience,’’ Cain told an audience at The National Press Club in Washington, “ I have never sexually harassed anyone.

“While at the restaurant association,’’ Cain said, “ I was accused of sexual harassment. Falsely accused, I might add.”

It is clear from the story that Politico posted Sunday evening that reporters had made extensive efforts to figure out what happened. But much of what appeared came from anonymous sources whose knowledge appeared to be second-hand or unspecific.

Politico described the incidents involved “conversations allegedly filled with innuendo or personal questions of a sexually suggestive nature” that took place at conferences or other restaurant association events. One exchange, an unnamed source said, involved an invitation by Cain to an employee to meet him in his hotel suite at an event. There were also “physical gestures that were not overtly sexual but that made women who experienced or witnessed them uncomfortable and that they regarded as improper in a professional relationship.’’

Obviously, this description leaves open a myriad of possibilities, from the boorish to the legally actionable. Certainly, it prompts readers to scratch their heads as they try to remember what in the late 1990s constituted a physical gesture that was not overtly sexual but discomfiting. (I checked. The Macarena came out in the mid-1990s.) Suggestions from a boss to “meet in my suite” are equally ambiguous. Did Cain have a sheaf of strategy papers on the desk or a CD player with a Michael Bolton track cued up?

Therein is the problem with this story. If the facts as published were part of a memo to Politico’s editors, they would amount to a first-rate tip on a story. If Cain turns out to be a serial harasser, it will surely tarnish his image as the 2012 campaign’s most likable fresh face.

Politico says it emailed the campaign for a response to the allegations on Oct. 20, and the answers quoted in Sunday’s story from both Cain and his spokesman are less than complete. But the onus remains on the news organization to nail down its story.

The unanswered questions include:

What exactly was said or done by Cain?

How much money was paid to each of the women?

If the story reached the board of the restaurant association, as Politico alleges, why do the chairman, vice chairman and immediate past chairman of the board all say they’ve never heard of it.

Sexual harassment is a potent charge. It has brought down CEOs, congressmen and senators, and very nearly pushed Bill Clinton out of the presidency. But in this case, it remains unclear whether this was merely a great tip or an actual bombshell. I respect Politico’s decision to keep the names of the women out of this, although they will surely emerge. Yet, the basic details of this “harassment’’ are essential so readers can judge its significance.