The Federal Bureau of Investigation (FBI) has taken note of a hypothesis proposed by a group of US experts and students that Al Qaeda leader Osama bin Laden was most likely hiding in northwest Pakistan. Using standard geographical tools routinely employed to locate endangered species and fugitive criminals, the group said there is a high probability that Bin Laden has been hiding in one of three buildings in the northwestern Pakistani city of Parachinar, a long-time hideout for mujaheedin fighters. "He may be sitting there right now," said Thomas W. Gillespie, a bio-geographer with the University of California, Los Angeles (UCLA) who led the study published online Tuesday in the MIT International Review. Gillespie told the Los Angeles Times that he and his students contacted the FBI's local field office before publishing their paper, but they haven't heard back. Laura Eimiller, a spokeswoman for FBI's Los Angeles bureau, was quoted as saying that the information was forwarded to two people working on the case, but "because it is an active investigation, it would not be appropriate" to comment on the information's fate. The study employed two geographic principles used to predict the distribution of wildlife. The first, "distance-decay theory", says as an animal -- or a human being -- moves away from its preferred habitat, the probability of finding a compatible environment decreases exponentially. The second principle, "island bio-geographic theory", holds that the animal or person is most likely to move into the largest, closest area that can fulfil all its needs. Gillespie and his students started with a satellite map centred on bin Laden's last known location, in Tora Bora, in eastern Afghanistan near the Pakistani border, the Los Angeles Times noted. They eliminated areas in Afghanistan because they were under the control of US forces at the time of bin Laden's disappearance. Then they evaluated the cities and towns in the remaining territory and calculated the likelihood that the Al Qaeda chief would have relocated there. They concluded that he must have trekked nearly two miles over mountainous terrain to the Pakistani tribal area of Kurram and settled in Parachinar, the largest city in the region, with a population of half a million. The researchers zeroed in further by searching satellite images for buildings with walls at least 10 feet high (for safety), at least three rooms (to house his bodyguards) and electricity (to power his kidney dialysis machine), among other features. The research thus led them to two compounds that are thought to be residences, and a third, with crenelated towers on the corners, that may be a prison or an army officers club. "You develop a testable hypothesis that can be accepted or rejected just like in any other type of science," Gillespie said. Such "geographic profiling techniques" have been used to capture criminals before, said Kim Rossmo, director of the Center for Geospatial Intelligence and Investigation at Texas State University. "This is a paper that should be paid attention to by the military and intelligence agencies for some of the ideas," Rossmo said. "But it's not going to be a case of, 'X marks the spot, there's Osama bin Laden.' "