FBI Director James Comey, when asked at the Aspen Security Forum in London on Friday how much the organization had paid, said: "A lot. More than I will make in the remainder of this job. But it was, in my view, worth it."

Comey's annual salary as of January 2015 was $183,300, according to figures from the FBI and the US Office of Management and Budget, meaning Comey will make a basic $1.34 million over the remainder of his seven years and four months in the job.

The payment would be the most the FBI has ever paid for a hacking job, beating the $1 million paid by US information security company Zerodium to break into phones.

Terrorist links?

The FBI gained access to the iPhone used by Syed Rizwan Farook, one of the shooters who along with his wife Tashfeen Malik killed 14 people in San Bernardino, California, on December 2. Both died in a firefight with police.

Law enforcement sources told CNN in December that Farook - who was born in Illinois but had Pakistani heritage - had been in touch with people being investigated by the FBI for international terrorism. The FBI said that it wanted access to the phone as part of its investigation into the attacks.

Hacked by an unknown third party

The US Justice Department said in March it had unlocked the San Bernardino shooter's iPhone with the help of an unidentified third party. A federal magistrate had directed Apple to help the FBI hack into the phone.

"Somebody approached us from outside of the government and said, 'We think we've come up with a solution.' And we tested and tested and tested it, and then we purchased it," Comey said.

It's a deal

The FBI has also dropped its case against Apple Inc, ending a potentially high-stakes legal clash but leaving the ongoing struggle over encryption unresolved.

The Apple-FBI legal showdown was set to become a high-profile case exposing the struggle between national security needs and privacy principles.

Apple - backed among others by Google and Facebook - was opposed to assisting the government in unlocking the phone on grounds it could have wide-reaching implications on digital security and privacy.

The FBI said it will now be able to use the software used on the San Bernardino phone on other 5C iPhones running IOS 9 software, Comey said. There are estimated to be about 16 million 5C iPhones in use in the US, while 84 percent of iOS devices are running iOS 9 software.

jbh/blc (Reuters, AP, AFP)