The White House is preventing the CIA director, Gina Haspel, or any other intelligence official from briefing the Senate on the murder of Saudi dissident and Washington Post columnist, Jamal Khashoggi.
The secretary of state, Mike Pompeo, and the defence secretary, James Mattis, are due to give a briefing on US relations with Saudi Arabia to the entire Senate behind closed doors on Wednesday, ahead of a vote that could cut off US support for Riyadhs military campaign in Yemen.
On a national security issue of such importance, it would be customary for a senior intelligence official to take part. On this occasion, the absence of the intelligence community is all the more glaring, as Haspel travelled to Istanbul to hear audio tapes of Khashoggis murder provided by Turkish intelligence, and then briefed Donald Trump.
Officials made it clear that the decision for Haspel not to appear in front of the committee came from the White House.
According to multiple reports, the tapes and other intelligence material point clearly to Crown Prince Mohammed bin Salman as having ordered Khashoggis killing in the Saudi consulate in Istanbul on 2 October.
The US president has asserted, however, that the CIA report is inconclusive a claim greeted with scepticism by many senators who expected to hear first-hand from Haspel on Wednesday on a brutal killing that appears to have help sway several senators against continuing military support to Riyadh for the war in Yemen.
That conflict is thought to have killed more than 50,000 people, with many of the casualties coming from the Saudi-led coalitions aerial bombing campaign. The coalitions use of economic blockades has meanwhile help bring the country to the brink of famine. Save the Children estimates that up to 85,000 children have died of hunger.
Against that backdrop the administration is increasingly nervous that the Senate will rebel against its policy of maintaining support for Riyadh and Prince Mohammed, asserting its powers under the War Powers Resolution.
As of Tuesday, however, the Senate was told by the administration to expect only Pompeo and Mattis at the Wednesday briefing. The White House did not respond to a query on the absence of an intelligence official.
There is always an intel person there for a briefing like this, a Senate staffer told the Guardian. It is totally unprecedented and should be interpreted as nothing less than the Trump administration trying to silence the intelligence community.
Bruce Riedel, a veteran CIA official and an expert on the US-Saudi relationship at the Brookings Institution, said: Gina [Haspel] has been the case officer on this. She traveled to Turkey and she is the one who listened to the tapes and is reported to have briefed the president multiple times.
This is further evidence that the White House is trying to outdo the Saudis in carrying out the worst cover-up in modern history, Riedel added.
The national security adviser, John Bolton, told reporters on Tuesday that he had not heard the tape of Khashoggis murder, and did not intend to.
People who speak Arabic have listened to the tape and given us the substance of whats in it, Bolton said a White House briefing. Pressed on why he had not listened to something of such potential importance to relations with Riyadh, he retorted: How many of you speak Arabic? I guess I should ask you why you think I should [listen]? What do you think I would learn from it?