FBI director James Comey was testifying in regarding the agency's work, the events in the run-up to the 2016 elections, and the upcoming reauthorization of the government's surveillance powers, but the figure was largely missed by reporters at the time.
"I was so struck when San Bernardino happened and you made overtures to allow that device to be opened, and then the FBI had to spend $900,000 to hack it open," said Feinstein. "And as I subsequently learned of some of the reason for it, there were good reasons to get into that device."
Immediately following the disclosure, Comey did not address or refute the figure.
Last year, the FBI and Apple were embroiled in a short but fierce legal battle over the company's refusal to unlock the phone of the San Bernardino terrorist, who in December 2015 killed 14 people and injured more than a dozen others in the California city. Apple argued it couldn't access the terrorist's iPhone 5c even if it wanted to because of the device's encryption. The FBI asked a court to force Apple to rework its software to bypass the encryption. The government eventually dropped the case when it unlocked the iPhone 5C with the help of an unnamed third party.
But Feinstein's reported $900,000 figure is at odds with Comey's, who said the third-party's expertise used to hack the device cost taxpayers over $1 million.
Comey said during a security conference in London last year that the hack cost "more than I will make in the remainder of this job -- which is seven years and four months for sure."
Reuters crunched the numbers using figures from the Office of Management and Budget, and calculated that Comey was projected, at the time, to earn about $1.34 million during the next seven years and four months -- not including bonuses and benefits.
The discrepancy between Feinstein's and Comey's statements are not known -- though, during the Apple and FBI lawsuit, Feinstein was the most senior ranking Democrat on the Senate Intelligence Committee -- and as a result, also a member of the "Gang of Eight," a set of eight members of Congress who are routinely briefed on the government's highly-classified operations.
Neither the FBI nor Feinstein's office responded to a request for comment.