TRIPOLI, Oct 18 (NYT) - If every rumor swirling around this seaport capital is true, someone tries to assassinate the Libyan leader Muammar el-Qaddafi -- oh, about every couple of months.

Most of the rumors, diplomats guess, must be fanciful, spun either from the wishful thinking of those who would dearly love to see an end to Colonel Qaddafi's 29-year reign or from the equally dark designs of security forces adept in the art of disinformation.

Real information in Libya is so scarce a commodity that the only generally accepted truth about most internal security matters is that no one really knows.

Still, a recent barrage of claims and counterclaims about who might have done what, and when, to a leader who is now hobbling on crutches has included so fulsome a dose of the unusual that -- even in a country with a reputation for the bizarre -- people are trying hard to piece together just what might be going on.

A tangle of clues includes a postponed trip, a broken leg, reports of a roadside ambush, and the untimely death of a provincial governor. But, as with videotape broadcast here last month that purportedly shows a 1996 assassination attempt by a British agent, no one is quite sure what, if anything, it adds up to.

"Something seems to have happened this summer, but a lot of fantasy has been mixed up with fact," a senior Western diplomat here said with about as much authority as it is possible for any foreign observer here to muster.

The latest speculation about Colonel Qaddafi, ignited by travelers' assertions in early June, was further fueled in late August when the Libyan leader looked weak and wan and sat in a wheelchair in a satellite television interview with CNN. Colonel Qaddafi explained in the interview that he had broken his thigh in a sporting accident.

But among Libya watchers, particularly those abroad, his unhealthy appearance has revived unanswered questions about what might have happened earlier in the summer, when a planned overland trip to Egypt was abruptly canceled on the day he was to have arrived, and when news agencies quoted travelers from Libya as saying that his convoy had come under attack near the eastern Libyan town of Benghazi.

Officially, Colonel Qaddafi, who led a military coup in 1969, is not even Libya's head of state; he is known simply as the leader of the revolution. But in practice, the 56-year-old Colonel and a tight circle of advisers continue to rule Libya with a heavy hand. And because he has never designated a successor, and is regarded as a pariah by the United States and Britain, real and reported accounts of attempts to overthrow him have been watched in the West for years with particular acuity.

In interviews here, nearly a dozen Arab and Western diplomats who have paid close attention to the case scoffed at the idea that there was any connection between any injury to Colonel Qaddafi and whatever might have happened this June. For a start, they said, Colonel Qaddafi appeared in public in Tripoli several days after the reported assassination attempt, in what seemed a deliberate attempt to discount the rumors that he had been attacked.

In one television appearance, he wore a short-sleeve shirt and even pointed defiantly to his left arm, openly mocking those who had been saying that it had been badly wounded in the supposed attack on his motorcade.

But on other questions, the diplomats, who under rules imposed by their governments would speak only on condition of anonymity, expressed sharply differing views. Some said they were all but certain that some kind of attack had taken place; others said they were all but certain that it had not.

All said there was little doubt that Colonel Qaddafi had not incurred any injury to his leg until about a month later, in early July, when he unexpectedly was carried out on a stretcher to meet with a visiting delegation.

But most also discounted the story that he had been injured while exercising; some suggested that there might have been another assassination attempt, while most said they believed that the truth had been far more mundane: that he had broken his thigh during a slip in the bathroom.

And, in a country in which the only official source of information is the state-controlled news outlets, all acknowledged that much remained unanswered about reported events this summer, including the death of the governor of Benghazi, who by some accounts was among those who tried to assassinate Colonel Qaddafi in June and by others was one of those wounded in that reported attempt.

Several weeks after the reported assassination, the governor was reported in official Libyan newspapers to have been killed after being struck in the forehead by a horse.

Among other unresolved mysteries has been why Colonel Qaddafi abruptly canceled his trip to Egypt scheduled for June 4. Explained by Libyan officials as deference to President Hosni Mubarak's busy schedule, the decision was greeted in Egypt with enough surprise that Mubarak was reported on the same day to have telephoned Colonel Qaddafi to inquire about his health.

The idea that Colonel Qaddafi faces internal challenges is not new. One biographer, George Tremlett, has written that there have been dozens of coup attempts, and some of them, including a 1993 attempt by soldiers from the Warfalla tribe, have resulted in publicly announced executions.

Among other clear indications of opposition to his rule, Western diplomats and reports by the United States Government have noted intensive clashes in 1995 between Libyan security forces and members of Islamic groups in eastern Libya, a 1996 prison riot that left hundreds of people dead and a 1996 clash at a soccer stadium in which a dispute over a referee's call against a team owned by one of Colonel Qadaffi's sons set off a riot in which people chanted anti-Qaddafi slogans. In that latter incident, even official Libyan news outlets reported that 9 people had been killed and 30 injured. Other accounts, given credence in a recent State Department report, have put the number of deaths to have been as high as 50.

As for reports of actual assaults against Colonel Qaddafi, Arab and Western diplomats in Tripoli say that many have been concocted by the Libyan security services and then spread as a way of testing public loyalty. But some who said they had begun to wonder whether everything had been fabricated said they had been given pause by a wrinkle that emerged last month, when a Libyan television broadcast appeared to substantiate rumors that an assassination attempt against Colonel Qaddafi had been made in 1996.

The images, broadcast by the London-based Arab satellite television channel ANN during a live interview with Colonel Qaddafi from Tripoli, showed the Libyan leader being greeted by crowds at a people's rally in Wadi Achatt, in the southern province of Fezzan, when a man threw what Colonel Qaddafi said was a hand grenade at him from less than three yards away.

The report said that the grenade did not explode, but the images did not show the grenade, nor did they show any indication of panic by either Colonel Qaddafi or his bodyguards. But the broadcast quoted Colonel Qaddafi as saying that the pictures substantiated recent assertions by a former British intelligence officer, David Shayler, that the British Government had been aware of and had supported an attempt to kill the Libyan leader that year.

The British Government has denied Shayler's accusations, and he has been detained by the French police since early August at the request of the British authorities. He is awaiting a ruling by a Paris court, scheduled for Oct. 21, as to whether he should be extradited to Britain to face charges under the Official Secrets Act.

As is often the case in Libya, though, the accounts conflict, adding to the element of mystery.

Shayler told the British Broadcasting Corporation that the attempt involved the planting of a bomb under Colonel Qaddafi's motorcade in February 1996.

He said the attempt was carried out by Muslim extremists who put the bomb under the wrong car, killing several bystanders.

But not only is that scenario different from the one shown on Libyan television, so is the apparent timing of the incidents, Tripoli-based diplomats say.

They say that the incident shown on Libyan television appeared to have taken place during an appearance by Colonel Qaddafi before a people's rally in Wadi Achatt during the summer of 1996, several months after the incident described by Shayler.