Los Angeles, Nov 16 (IANS) The CIA has paid millions of dollars to Pakistan's Inter-Services Intelligence (ISI) since 9/11, 'accounting for as much as one-third of the foreign spy agency's annual budget', says a media report.

The ISI also collected 'tens of millions of dollars through a classified CIA programme', which pays for the capture or killing of wanted militants, the Los Angeles Times reported Monday citing current and former US officials.

An intense debate has been triggered within the US government due to 'long-standing suspicions that the ISI continues to help Taliban extremists who undermine US efforts in Afghanistan and provide sanctuary to Al Qaeda members in Pakistan'.

But US officials have continued to make the payments as ISI's assistance is considered critical: 'Almost every major terrorist plot this decade has originated in Pakistan's tribal belt, where ISI informant networks are a primary source of intelligence.'

The report went on to say that the payments to Pakistan are authorised under a covert programme initially approved by then president Bush and continued under President Obama.

'The ISI has used the covert CIA money for a variety of purposes, including the construction of a new headquarters in Islamabad, the capital. That project pleased CIA officials because it replaced a structure considered vulnerable to attack; it also eased fears that the US money would end up in the private bank accounts of ISI officials.'

'What we didn't want to happen was for this group of generals in power at the time to just start putting it in their pockets or building mansions in Dubai,' a former CIA operative was quoted as saying.

CIA officials argue that their own disbursements - particularly the bounties for suspected terrorists - should be considered a bargain.

'They gave us 600 to 700 people captured or dead,' a former senior CIA official, who worked with the Pakistanis, was quoted as saying.

'Getting these guys off the street was a good thing, and it was a big savings to (US) taxpayers.'

Another US intelligence official said Pakistan had made 'decisive contributions to counter-terrorism'.

'They have people dying almost every day,' the official said. 'Sure, their interests don't always match up with ours. But things would be one hell of a lot worse if the government there was hostile to us.'

The ISI is a highly compartmentalised intelligence service, with divisions that sometimes seem at odds with one another. Units that work closely with the CIA are walled off from a highly secretive branch that has directed insurgencies in Afghanistan and Kashmir, the Los Angeles Times report said.

'There really are two ISIs,' the former CIA operative said.

'On the counter-terrorism side, those guys were in lock-step with us,' the former operative said. 'And then there was the 'long-beard' side. Those are the ones who created the Taliban and are supporting groups like Haqqani.'

The network led by Jalaluddin Haqqani has been accused of carrying out a series of suicide attacks in Afghanistan, including the 2008 bombing of the Indian Embassy in Kabul.