Four thousand pages of records locked away as a state secret are to be published in the next fortnight.
Their release was ordered after a minister agreed to personally review the files which were only uncovered as part of the Mirror's two-year Nuked Blood investigation. The Ministry of Defence had denied for years ever having them.
The records are thought to have never been disclosed to veterans or their lawyers when they brought repeated legal cases against the MoD for exposing them to radiation, raising questions about whether the High Court, Supreme Court, and European Court of Human Rights have been intentionally misled.
Now campaigners have learned they are due to be released, after defence minister Andrew Murrison waged a four-month battle with his own officials to see them for himself.
It comes less than six months after we revealed that the Atomic Weapons Establishment had admitted holding 150 records on blood and urine testing of servicemen, civilians and indigenous people during the nuclear trials, which were held in Australia and the Pacific between 1952 and 1967.
Millionaire who killed son, 8, with pill overdose found dead in apartmentThey had titles including "medical report - blood count data", "report on medical examinations of natives", and "blood examinations". The MoD denied having any such information in 2018, but after they were uncovered in a Freedom of Information request insisted that they did not include any medical records or blood data, and contained no information about individuals.
But campaigners have been told some of the files to be released will be redacted - because they contain personal data.
A government source said: "Andrew has personally read every file, and ordered the release of every single one. He genuinely thinks they're innocuous, but the question remains that if that's the case, why were they locked away as a state secret? It just doesn't make any sense."
Murrison is expected to announce the publication with a written statement to Parliament in the next fortnight.
The AWE has admitted the files are all held on a secret database called Merlin, which has been locked away from public view on the grounds that it is a risk to national security, could aid terrorists, or damage international relations.
Although lawyers acting for veterans over the years have been able to submit keyword searches, no-one outside the AWE has ever known it holds information about blood testing, or had full access to it.
Blood tests are the only way to know if radiation entered someone's body and altered how it functions, and could explain the veterans' legacy of ill health, miscarriages for their wives and birth defects in their children.
Campaigners served legal papers on the MoD last month, threatening to take them to court to force disclosure of the documents if the MoD refused to produce them. They also offered a one-year special inquiry to get to the bottom of the matter.
The veterans' lawyers are unable to comment on any ongoing correspondence at this stage.