As suspicions grow about how Osama bin Laden spent years living next door to Pakistan's military, there are indications emerging that the terrorist mastermind was sheltered by one of the militant groups that has enjoyed tolerance, if not support, from Pakistani security services.

A police officer familiar with Mr. bin Laden's compound in the scenic town of Abbottabad said the location was used by Hizbul Mujahedeen, one of the biggest militant outfits in the disputed territory of Kashmir. Like other groups fighting Indian troops in the borderlands, HM's radical membership has never been rounded up by Pakistani forces and some analysts say Islamabad covertly supports the group.

Any link to HM would deepen Pakistan's embarrassment over Mr. bin Laden's death. Pakistan has denied any collusion with terrorists, saying that its leading intelligence service had been sharing information with U.S. counterparts since 2009 about the compound where Mr. bin Laden was found.

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Still, in the wake of the raid, Islamabad scrambled to ensure that precise ownership of the compound would not become public knowledge.

"The place belonged to Hizbul Mujahedeen," the police officer said. "But the authorities have asked us not to share any information about the exact ownership."

Land-registry officials in Abbottabad, known in the local language as patwaris, were summoned to a meeting on Tuesday and urged to keep quiet.

"The patwaris are meeting right now," a local official said. "They are being instructed not to say anything about the land-ownership issue."

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American officials have described the owners as "brothers," and neighbours recalled seeing a pair of men, possibly ethnic Pashtuns from the rugged western frontier, who largely kept to themselves.

Their names were reported in local media as Bara Khan and Chota Khan, or Arshad Pathan and Chota Pathan. However, "Bara" and "Chota" are common vernacular for "older," and "younger," making the names almost meaningless.

A Pakistani official said the mystery surrounding the two men has deepened with the discovery that their national identity cards were faked.

Demands grew louder on Tuesday for an investigation that would determine what support Mr. bin Laden received inside Pakistan.

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"If I were a prosecutor at the United States Department of Justice … I would be tempted to call a grand jury," wrote Steve Coll, a Pulitzer-winning biographer of Mr. bin Laden. "Who owned the land on which the house was constructed?"

If the ownership were traced to HM, it would mark an unusual example of co-operation between the militant group and its more extreme cousin, al-Qaeda. HM has maintained a narrow focus on removing Indian forces from Kashmir, while Al-Qaeda pursues global ambitions.

"This is the first time I've heard of links between Hizbul Mujahedeen and Osama, but its members would probably admire him," said Kamran Bokhari of Stratfor international analysts.

Pakistan's Foreign Office issued its first detailed statement about the raid on Tuesday afternoon, making oblique reference to the suspicions raised by the fact that Mr. bin Laden apparently lived near a prominent military school, in a garrison town dominated by security forces.

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"There has been a lot of discussion about the nature of the targeted compound, particularly its high walls and its vicinity to the areas housing Pakistan Army elements," the government said. "It needs to be appreciated that many houses occupied by the affectees of operations in [tribal areas]have high boundary walls, in line with their culture of privacy and security."

The idea that Mr. bin Laden's presence went unnoticed did not sit well with Pakistan's media, however. Dawn, a leading newspaper, pointed out that the head of the country's military, General Ashfaq Kayani, had visited the nearby Kakul Military Academy on April 23 and bragged that his forces had broken the "terrorist backbone" in the country.

"Was the general completely unaware that the most wanted man lived but a short distance away?" the newspaper asked, in a sharply worded front-page analysis.

Another major newspaper, The Nation, expressed similar sentiments in an unsigned report on the front page: "The presence of the world's most wanted terrorist in such a strategically sensitive city is beyond the understanding of a sane man."

Muzammil Pasha is Special to The Globe and Mail