Evidence uncovered in 2002 links the Saudi Arabian government with the September 11, 2001 attacks, anonymous US officials revealed to the British Times Wednesday.
US authorities discovered the flight certificate of would-be hijacker Ghassan Al-Shrabi in an envelope from the Saudi embassy to Washington during the latter's 2002 arrest in Pakistan, the officials revealed.
Details about the certificate and other documents were quietly released by officials in 2015, in a memo entitled Document 17 from back in 2003.
However, they only came to light to the general public this week, after being referenced by a popular blogger, the Daily Mail reports.
The revelation surfaces amid an historic visit Wednesday morning by US President Barack Obama to Riyadh and an ongoing debate over whether to release 28 sealed documents about the attacks.
Conspiracy theories about the Saudi government's involvement in the attacks have reigned for years, as 15 of the 19 hijackers were Saudi. Al Qaeda leader Osama Bin Laden's family has close ties to the Saudi royal family, further spawning rumors and speculation.