The US has been urged to disclose evidence of UFOs after a whistleblower former intelligence official said the government has possession of “intact and partially intact” alien vehicles. The former intelligence official David Grusch, who led analysis of unexplained anomalous phenomena (UAP) within a US Department of Defense agency, has alleged that the US has craft of non-human origin. Information on these vehicles is being illegally withheld from Congress, Grusch told the Debrief. Grusch said when he turned over classified information about the vehicles to Congress he suffered retaliation from government officials. He left the government in April after a 14-year career in US intelligence. Jonathan Grey, a current US intelligence official at the National Air and Space Intelligence Center (Nasic), confirmed the existence of “exotic materials” to the Debrief, adding: “We are not alone.” The disclosures come after a swell of credible sightings and reports have revived attention in alien ships, and potentially visits, in recent years. In 2021, the Pentagon released a report on UAP – the term is preferred to UFO by much of the extraterrestrial community – which found more than 140 instances of UAP encounters that could not be explained. The report followed a leak of military footage that showed apparently inexplicable happenings in the sky, while navy pilots testified that they had frequently had encounters with strange craft off the US coast. In an interview with the Debrief journalists Leslie Kean and Ralph Blumenthal, who previously exposed the existence of a secret Pentagon program that investigated UFOs, Grusch said the US government and defense contractors had been recovering fragments of non-human craft, and in some cases entire craft, for decades. “We are not talking about prosaic origins or identities,” Grusch said. “The material includes intact and partially intact vehicles.” Grusch told the Debrief that analysis determined that this material is “of exotic origin” – meaning “non-human intelligence, whether extraterrestrial or unknown origin”. “[This assessment is] based on the vehicle morphologies and material science testing and the possession of unique atomic arrangements and radiological signatures,” Grusch said. Grey, who, according to the Debrief, analyzes unexplained anomalous phenomena within the Nasic, confirmed Grusch’s account: “The non-human intelligence phenomenon is real. We are not alone. Retrievals of this kind are not limited to the United States. This is a global phenomenon, and yet a global solution continues to elude us.” The Debrief spoke to several of Grusch’s former colleagues, each of whom vouched for his character. Karl E Nell, a retired army colonel, said Grusch was “beyond reproach”. In a 2022 performance review seen by the Debrief, Grusch was described as “an officer with the strongest possible moral compass”. Nick Pope, who spent the early 1990s investigating UFOs for the British Ministry of Defence (MoD), said Grusch and Grey’s account of alien materials was “very significant”. “It’s one thing to have stories on the conspiracy blogs, but this takes it to the next level, with genuine insiders coming forward,” Pope said. “When these people make these formal complaints, they do so on the understanding that if they’ve knowingly made a false statement, they are liable to a fairly hefty fine, and/or prison. People say: ‘Oh, people make up stories all the time.’ But I think it’s very different to go before Congress and go to the intelligence community inspector general and do that. Because there will be consequences if it emerges that this is not true.” The Debrief reported that Grusch’s knowledge of non-human materials and vehicles was based on “extensive interviews with high-level intelligence officials”. He said he had reported the existence of a UFO material “recovery program” to Congress. “Grusch said that the craft recovery operations are ongoing at various levels of activity and that he knows the specific individuals, current and former, who are involved,” the Debrief reported. In the Debrief article, Grusch does not say he has personally seen alien vehicles, nor does he say where they may be being stored. He asked the Debrief to withhold details of retaliation by government officials due to an ongoing investigation. He also does not specify how he believes the government retaliated against him. In June 2021, a report from the Office of the Director of National Intelligence said that from 2004 to 2021 there were 144 encounters between military pilots and UAP, 80 of which were captured on multiple sensors. Only one of the 144 encounters could be explained with “high confidence” – it was a large, deflating balloon. Following increased interest from the public and some US senators, the Pentagon established the All-domain Anomaly Resolution Office, charged with tracking UAP, in July 2022. In December last year, the office said it had received “several hundred” new reports, but no evidence so far of alien life. The publication of Grusch and Grey’s claims comes after a panel that the US space agency Nasa charged with investigating unexplained anomalous phenomena said stigma around reporting encounters – and harassment of those who do report encounters – was hindering its work. The navy pilots who in 2021 shared their experiences of encountering unexplained objects while conducting military flights said they, and others, had decided against reporting the encounters internally, because of fears it could hinder their careers. “Harassment only leads to further stigmatization of the UAP field, significantly hindering the scientific progress and discouraging others to study this important subject matter,” Nasa’s science chief, Nicola Fox, said in a public meeting on 31 May. Dr David Spergel, the independent chair of Nasa’s UAP independent study team, told the Guardian he did not know Grusch and had no knowledge of his claims. The Department of Defense did not immediately respond to a request for comment. In a statement, a Nasa spokesperson said: “One of Nasa’s key priorities is the search for life elsewhere in the universe, but so far, NASA has not found any credible evidence of extraterrestrial life and there is no evidence that UAPs are extraterrestrial. However, Nasa is exploring the solar system and beyond to help us answer fundamental questions, including whether we are alone in the universe.” Pope said in his work investigating UFOs for the MoD he had seen no hard evidence of non-human craft or materials. “Some of our cases were intriguing,” Pope said. “But we didn’t have a spaceship in a hangar anywhere. And if we did, they didn’t tell me.” Still, Pope said, Grusch’s claims should be seen as part of an increasing flow of information – and hopefully disclosures – about UFOs. He said: “It’s part of a wider puzzle. And I think, assuming this is all true, it takes us closer than we’ve ever been before to the very heart of all this.”