Washington, May 7 (IANS) The United States has demanded from Pakistan the identities of some of their top intelligence operatives to determine whether any of them had contact with Osama bin Laden or his agents, according to a media report.

The demand came in the wake of Pakistan's failure to locate the bin Laden hideout in Abbottabad, just 35 north of Islamabad, where the Al Qaeda leader was killed by US forces in a raid early Monday morning, the New York Times reported citing Pakistani officials.

There is, the Times said, growing suspicion among United States intelligence and diplomatic officials that someone in Pakistan's secret intelligence agency knew of bin Laden's location, and helped shield him.

Obama administration officials have stopped short of accusing the Pakistani government - either privately or publicly - of complicity in the hiding of bin Laden in the years after the Sep 11, 2001 terror attacks on the World Trade Centre and the Pentagon.

US officials, it said, expressed deep frustration with Pakistani military and intelligence officials for their refusal over the years to identify members of the agency, the Inter-Services Intelligence Directorate, who were believed to have close ties to bin Laden.

In particular, American officials have demanded information on what is known as the ISI's S directorate, which has worked closely with militants since the days of the fight against the Soviet army in Afghanistan, the Times said.

"It's hard to believe that Kayani and Pasha actually knew that Bin Laden was there," a senior administration official cited by the daily said, referring to Pakistan's army chief, Gen Ashfaq Parvez Kayani, and the ISI director-general, Lt Gen Ahmad Shuja Pasha.

But, he added, "there are degrees of knowing, and it wouldn't surprise me if we find out that someone close to Pasha knew."

Already, Pakistani news outlets have been speculating that Pasha, one of the most powerful figures in Pakistan, may step down as a consequence of the Bin Laden operation.

Raising questions of how Pakistani officials could not know there was a suspicious compound in their midst, Hassan Abbas a former Pakistani official now teaching at Columbia University told the Times: "If he was there since 2005, that is too long a time for local police and intelligence not to know."