Doubt over Steve Fossett’s remains

When the wreckage of his crashed airplane was discovered on Wednesday, it was widely assumed the rabid speculation about what happened to Sir Richard Branson's American balloonist friend Steve Fossett (pictured) would come to an end. However, while bones were found near the wrecked aircraft, the investigators are already casting doubt on whether or not they are human.

Hopes of finally resolving the mystery now hinge on a two-inch fragment of bone. DNA tests will be carried out on the sample, the only body part found among debris spread over a remote 400ft by 150ft area high in the Sierra Nevada mountains in eastern California, but Federal investigators are claiming the sample is not enough to provide DNA to coroners.

Fossett's plane was discovered after specialist dogs, trained to sniff out human remains, were sent to the site 10,000ft up in the mountains west of the skiing town of Mammoth Lakes. The search team discovered Fossett's pilot licence and other identification cards nearby.

Since Fossett, 63, disappeared, conspiracy theories have abounded. Some talk of him faking his own death, although there appear to be no reasons for him to do this. More fanciful conjecture has it that he was abducted by aliens – the area where he disappeared is not far north of Area 51, one of the most secretive places in the world and the subject of UFO speculation. Another theory was that he strayed into "a secretive military controlled area that's off limits to civilians or to all but a tiny number of military".

However, his wife Peggy appears convinced that the matter is now resolved. She said: "I hope now to be able to bring to closure a very painful chapter in my life." Richard Branson was more cautious. He said it he thought it "relatively likely" that Fossett's body would be found within the next couple of days.