Trump's presidential campaign did not immediately respond to a request for comment.
A 10-inch-thick document consisting of around 3,000 pages of top-secret material linked to the United States’ probe of Russia's interference in the 2016 presidential election and Moscow's connection with former President Donald Trump has been missing since the final days of his presidency, top sources told Reuters.
It was learnt that shortly before he left office, Trump ordered the CIA to provide a binder containing the Russia intelligence along with other documents so he could declassify information pertaining to the FBI's investigation into Russian meddling in the 2016 election.
According to the sources, the Russia papers contained highly sensitive raw intelligence that the United States and its NATO partners had obtained, which stoked concerns that the information gathering techniques might have been compromised.
Trump's presidential campaign did not immediately respond to a request for comment.
The Office of the Director of National Intelligence in January 2017 released an assessment that found Russian President Vladimir Putin and his government conducted a campaign of disinformation and cyberattacks to “help … Trump’s election chances” by denigrating his Democratic foe, Hillary Clinton.
Russia disputes that it meddled in the election.
According to the source, the administration offered to brief the Senate Intelligence Committee last year after the disappearance of the binder aroused such serious concerns, and the committee accepted.
The binder was characterised as being ten inches thick in a federal court document that conservative journalist John Solomon submitted in August.
Solomon was appointed by Trump as a representative with access rights to National Archives documents pertaining to his administration.
According to the document, Mark Meadows, who served as Trump’s last chief of staff, was involved in handling the missing binder and developing with Solomon a strategy to release the materials that Trump planned to declassify.
Meadows did not immediately respond to a request for comment made via the Conservative Partnership Institute, where he is a senior partner.
The source said the binder contained other information related to the FBI's "Crossfire Hurricane" investigation, including materials on the origins of the probe collected by Trump aides and botched FBI applications for wiretap warrants.
They also included anti-Trump text messages between Peter Strzok and Lisa Page, FBI officials who were involved in the probe, the source said.
Much of that material is not considered sensitive, said the source.
It was covered in a heavily redacted version of the binder that was declassified and posted in five parts on the FBI’s website in 2022.
Trump has repeatedly called the FBI investigation a hoax.
Solomon’s federal court filing said that just before Trump left office after his defeat by U.S. President Joe Biden, Solomon was told by Meadows that Trump intended to order the declassification of the Crossfire Hurricane materials in the binder.
Two days before his term ended, the document said, Trump and Meadows told Solomon that the binder had been declassified. On Jan. 19, Meadows invited Solomon to the White House to review several hundred declassified pages and discuss the materials’ public release, it said.
Copies were provided to Solomon. As he began preparing a story for his website, it continued, he received a call from the White House asking that copies be returned for additional redactions.
“Meadows promised Solomon that he would receive the revised binder,” said the document. “This never happened.”
There has been no trace of the classified version since then.