It’s the kind of story nobody wants to believe, a shabby tale of political dirty tricks that belongs in a third-string banana republic. But it has persisted ever since the Inauguration of Ronald Reagan in 1981, when Iran released the American hostages just minutes after he was sworn in. Had the Reagan campaign cut a deal with Ayatollah Ruhollah Khomeini to hold onto the prisoners long enough to ensure Reagan’s election? There’s no smoking gun, and Reagan’s men and the Bush White House continue to deny the story indignantly-but it cropped up again last week, with a few new giblets of circumstantial evidence. It was yet another blow to the Reagan image, currently under assault from revisionist historians and poison-pen biographers alike.

The story broke on two fronts: first in a New York Times op-ed piece by Gary Sick, who was the Iran expert on Jimmy Carter’s National Security Council, then in a PBS “Frontline” documentary. Both covered roughly the same ground, including the new allegation that the late CIA chief William Casey, then Reagan’s campaign director, began negotiating the deal with an Iranian cleric in two meetings in Madrid in July and August 1980. But if there was any real news, it was that Sick, a respected Columbia University professor who has doubted the story for years, has finally been convinced that something improper probably occurred. The evidence, he told NEWSWEEK, is “a consistent pattern of activity, with stories from a lot of people [and] a political logic … When I look at the whole lot of it, I cannot conclude that nothing happened.”

The “pattern” that persuaded Sick is an intriguing set of facts. Back in 1980 Republican campaign officials acknowledged that Reagan’s people were worried that Carter would bring the hostages home in time to get a dramatic lift at the polls. Hoping to discount such news in advance, the Reagan camp leaked warnings of an “October surprise.” Richard Allen, candidate Reagan’s foreign-policy adviser and later national-security adviser, has said that he met with an arms dealer who offered “to deliver the hostages to the Reagan forces.” (Allen says he dismissed the proposal as “absolutely lunatic.”) The Carter administration’s negotiations with Iran, which had been promising, stalled abruptly after September. In January the Iranians agreed to free the 52 American hostages, but they put off the actual release for hours until Reagan was sworn in. Soon after the Inauguration, planeloads of military equipment were going via Israel to Iran–a pattern that foreshadowed the later Iran-contra scandal.

That suggestive plot line turns into a full-fledged conspiracy in the testimony of a mixed bag of sources, cited both in Sick’s op-ed article and the TV documentary. (Sick is working on a book about Iran policy, and he was also interviewed for the show; he and the producers have shared information.) The arms dealer who says he offered the deal to Allen, Houshang Lavi, said on “Frontline” that Allen’s colleague Laurence Silberman actually told him, “We had our own contacts.” Another arms dealer, Jamshid Hashemi, said he and his brother Cyrus set up the Madrid meetings between Casey and Khomeini’s representative, Mehdi Karrubi. Former Iranian president Abolhassan Bani Sadr said he knew of the proposed deal; in his own book, out this week, Bani Sadr says he was told by Khomeini’s nephew-though he has no hard proof Other sources said the deal was sealed at two meetings in October in Paris, and at Casey was there. Three sources said they saw George Bush on the scene. The White ix House again denied that.

The evidence is far from conclusive. Many of the sources are shadowy figures of dubious credibility, and they haven’t come up with conclusive proof that Reagan’s men made actual deals or even attended the alleged meetings. Casey, of course, is dead and unable to offer his version. The Iranians may have broken off official talks with the United States because the Iran-Iraq War had begun. Khomeini may have delayed the hostages’ release out of personal pique at Carter. And Israel had reason to sell arms to Iran, to offset the growing power of Iraq.

But Sick argues that there are more than 15 people on three continents who tell stories that vary in detail but don’t conflict. In the end, Sick acknowledges, “I can’t prove every step of the way. My point is, isn’t there a question here that deserves to be examined?”

Many agree. Moorhead Kennedy, a former foreign service officer who was among the hostages, called last week for a special prosecutor or congressional inquiry to look into the charges. But skeptics remain, and among them is Warren Christopher, the former deputy secretary of state who ran the Carter negotiations with Iran. Despite considerable respect for Sick, Christopher still doesn’t credit the conspiracy: “I find the whole idea so abhorrent,” he says, “that I guess I find it very hard to believe it.” But just because the suspicions are so ugly does not mean they will go away.