By Adam Brookes
BBC News, Washington
CIA director General Michael Hayden has confirmed that his agency destroyed videotapes taken during the interrogations of two al-Qaeda suspects soon after 9/11.
CIA chief Gen Michael Hayden now faces a public test of his credibility
His statement to CIA employees was widely reported nationwide by Thursday evening.
Gen Hayden - ex-Air Force Intelligence, ex-National Security Agency, amiable and widely respected - now faces a public test of his credibility.
It is a moment that seems to come to all CIA directors these days.
Think George Tenet - still widely referred to around Washington as Mr Slam Dunk, for his famous assertion that Iraq had stockpiled weapons of mass destruction.
Think Porter Goss, whose tenure at the agency was brief and fractious, and whose run-ins with senior spies led to resignations - which rapidly became public.
Gen Hayden said the suspects were detained under the CIA's "terrorist detention and interrogation programme" - widely understood to mean the apparatus of secret detention facilities, locations unknown but possibly in Eastern Europe, where the presumed ringleaders of 9/11 and other terrorist plots were held before their transfer to Guantanamo Bay last year.
In these facilities, coercive interrogation techniques were used.
The row is likely to trigger more questions about interrogation techniques
The videotapes presumably showed which techniques were used, how often they were employed and what results they got.
In short, those tapes might answer once and for all the question of whether or not US personnel used techniques that would constitute "torture" under US or international law.
Now, we've learned, those tapes were destroyed.
Gen Hayden says they posed a security risk: they could expose the CIA interrogators shown on them to al-Qaeda reprisals.
The general also says that their contents had been documented in detail and they were not pertinent to any of the legal investigations and court cases that have requested from the CIA details of detainee interrogations.
And, says the CIA, all the interrogation techniques shown were legal.
The question for the CIA now will be this: will anybody - lawyers for detainees or human rights activists or congressional investigators or even just bloody-minded opponents of the Bush administration - be able to make a case that the CIA, by destroying the tapes, was destroying evidence?
The Center for Constitutional Rights (CCR) in New York has been one of the most dogged litigants in opposing the Bush administration's detention policies in the so-called War on Terrorism.
A spokeswoman for the CCR said that the videotapes would have been "directly pertinent" to litigation they had been involved in.
She said the CIA would have been aware of requests under the Freedom of Information Act for such materials when they destroyed them.
"The CIA blatantly lied during pending litigation," she said.
The Senate Intelligence Committee has said it will investigate.
The Democratic presidential contender, Hillary Clinton, said she would be "looking into it vigorously", and to find out "what the CIA was trying to protect".
The controversy comes at an unfortunate moment for Gen Hayden.
In Washington, a sense is just taking hold that intelligence reform is beginning to bite, and the spy agencies have begun shaking off the embarrassments, analytic failures and low morale of recent years.
Water boarding: prisoner bound to a board with feet raised, and cellophane wrapped round his head. Water is poured onto his face and is said to produce a fear of drowning
Cold cell: prisoner made to stand naked in a cold, though not freezing, cell and doused with water
Standing: Prisoners stand for 40 hours and more, shackled to the floor
Belly slap: a hard slap to the stomach with an open hand. This is designed to be painful but not to cause injury
Source: ABC News
The recent National Intelligence Estimate on Iran - which upended the Bush administration's assertions that Tehran is actively seeking a nuclear weapon - has been taken as evidence of a newly invigorated ability to "speak truth to power".
"The intelligence agencies are showing a renewed professionalism," one military intelligence officer said to me recently.
"They're refusing to accept political interference and are saying what they think."
Another source with close links to the intelligence community said: "It's a process which you've seen in the military under [Robert] Gates [the defence secretary], and it's now happening in the intelligence agencies."
It was, he said, connected to the "waning power of the Bush presidency".
Many in America's national security establishment will be disappointed if the arduous rebuilding of the CIA's credibility is interrupted, or if Gen Hayden's position is undermined because of decisions which were not taken on his watch.
Nonetheless, it appears that the agency has another unpredictable and potentially damaging controversy on its hands.
One final question to ponder: are there other videotapes of interrogations, which were not destroyed? And what would it take to get them released?