Washington: Pakistan's powerful spy agency ISI considered the US its "worst enemy" and Islamabad's cooperation with Washington was just a sham to extract billions of dollars in aid, said the doctor who was jailed for helping the CIA hunt down Osama bin Laden.

In an exclusive interview with Fox News, Shakil Afridi who helped track down Osama's Abbottabad compound before the May 02 raid by US commandos, described torture at the hands of the ISI.

He said the agency was openly hostile to the US.

"They said, 'The Americans are our worst enemies, worse than the Indians'," Afridi, who spoke from inside Peshawar Central Jail, was quoted as saying.

He added: "I tried to argue that America was Pakistan's biggest supporter ... but all they said was, 'These are our worst enemies. You helped our enemies'."

"I tried to argue that America was Pakistan's biggest supporter - billions and billions of dollars in aid, social and military assistance -- but all they said was, 'These are our worst enemies. You helped our enemies'."

Afridi helped the CIA by running a fake vaccination programme that allowed him to collect the DNA of bin Laden's children from the family compound in Abbottabad.

Sample analysis confirmed the terror chief was probably there and triggered the deadly mission by US Navy SEALS in May last year.

Pakistani officials felt the operation was a violation of the country's sovereignty.

After the raid, Afridi was arrested for conspiring against Pakistan, and last month jailed for 33 years.

The doctor also pointed out that the ISI helps fund the Haqqani network and spy agency also works against the US by preventing the CIA from interrogating militants captured by Pakistan, who are routinely released to return to Afghanistan to continue attacks on NATO forces there.

"It is now indisputable that militancy in Pakistan is supported by the ISI… Pakistan's fight against militancy is bogus. It's just to extract money from America," the doctor said, referring to the USD 23 billion Pakistan has received, largely in military aid, since 9/11.