Facts have an unfortunate habit of ruining otherwise vastly entertaining conspiracy theories. Which is precisely what seemed to happen yesterday when the wreckage of the supposedly “crash proof” Bellanca 8KCAB aircraft of Steve Fossett was discovered in the freezing wilderness of the Sierra Nevada Mountains in California.

So much for the theory that Fossett — a commodities trader from Chicago before he became famous for breaking solo aviation records — flew south of the border and changed his identity to escape either an impending divorce settlement or some catastrophic bets in the sub-prime mortgage sector.

Or that he was abducted by aliens. Or that his aircraft crashed with a B52 bomber loaded with nuclear weapons and was disposed of by a US military containment crew.

Until the body of Fossett is discovered and an explanation — such as an ageing adventurer made a fatal error at the controls or that he was taken ill in the air — comes to light the conspiracy theorists are unlikely to be satisfied.

After all, the raw material is too good to resist: the daredevil lifestyle; the high-tech gadgetry; other women; the alleged secret double life; the friendships with billionaires such as Sir Richard Branson and Barron Hilton; the widow who managed to have Fossett declared dead without a body — even though in the state of Illinois this typically takes seven years — the estate worth anywhere from $10 million to $100 million and, of course, the fact that the adventurer was last seen flying solo over the Nevada desert, home of the fabled alien research facility Area 51.

The words “Steve Fossett” and “faked death” is a popular Google search term, guaranteed to deliver an audience of excitable fanatics to even the most obscure of bloggers.

Why else would he have left his first aid kit behind, along with his pilot’s GPS watch? Why else would he have taken only a single bottle of water?

Even the authorities seemed seduced by the possibility of Fossett shenanigans. Take John Anderson, the Madera County Sheriff. Yesterday he speculated that Fossett might not only have survived but also retained the energy to hike through the mountains to deposit his ID cards and cash in a bush, where they could be found. “There must be some reason those things were found there,” he said, darkly.

Some reason? No mention of the possible one given by Preston Morrow, the hiker who found the items: that a wild animal may have dragged them there.

Sheriff Anderson is only the latest in a long line of officials to come over all wild-eyed with regard to the Fossett case. Lieutenant-Colonel Cynthia Ryan, of the US Civil Air Patrol, said in July: “I’ve been doing this search and rescue for 14 years. Fossett should have been found. It’s not like we didn’t have our eyes open. We found six other planes while we were looking for him. We are pretty good at what we do.”

Lieutenant-Colonel Ryan, who has since been relieved of her press duties, concluded that Fossett might have staged his own death. The Civil Air Patrol said that her comments “contain errors of fact, appear to be taken out of context, and were not released with the knowledge or approval of CAP”.

No such consideration was given to the possibility that the search team, which comprised Black Hawk helicopters fitted with infra-red technology — and supported by 30 or so private aircraft — might have been looking in the wrong place. Another doubter turned up in the form of Robert Davis, a risk assessor who claimed to have investigated the Fossett case for the Lloyd’s of London insurance market, which he said had issued a £25 million policy on the life of the adventurer.

“What I’ve strived to find out is what happened to this man in the run-up to his disappearance; why did he disappear?” he said. “I spoke to reporters who were on the scene, people who were helping out with the search efforts, anyone whom I thought could shed some light on this. I discovered that there is absolutely no proof that Steve Fossett is actually dead.

“I’m not a conspiracy theorist, I’m a man who deals in facts. What I am interested in is the truth — and a proper criminal investigation of this man’s disappearance was never undertaken by law enforcement or officials in the state of Nevada,” he added.

He went on to repeat several often cited oddities about the disappearance: that only one witness saw him take off from Mr Hilton’s Flying-M Ranch near Reno (this ignores Fossett’s contact with air traffic control); that Fossett asked the witness in question to prepare the aircraft for take-off even though he had never allowed anyone to do this before (there is no supporting evidence for this); and that he took off without any emergency equipment (not unusual for a short pleasure flight). Mr Davis also claimed that Fossett’s choice of aircraft was interesting: the Bellanca had a lightweight frame that could be dismantled easily.

As for the criminal investigation, the state of Nevada did not start an investigation after concluding that there was no evidence upon which such a case could be based.

Mr Davis could not be reached yesterday, but the existence of a life insurance policy has been denied by lawyers acting for Peggy Fossett, the widow of the adventurer. Lloyd’s said that Mr Davis never conducted an investigation directly for them.

So far the claims that Fossett had multiple mistresses do not add up to much more than second-hand information. One woman apparently said that she was in a relationship with the adventurer until his death, and said she knew of other women.

Even if this was true, would it have been enough to convince a man such as Fossett to give up everything by disappearing or commiting suicide? It seems unlikely.

Meanwhile, the claims of financial distress have been denied. “His estate is large and debt free,” said Mike LoVallo, a lawyer for Mrs Fossett, only a few weeks ago.

Which leaves one overwhelmingly probable possibility: that the body parts discovered in the wreckage will prove without a shadow of doubt that Fossett is dead. Unless, that is, they turn out to be the remains of someone else.

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