Omar al-Bayoumi was allegedly a Saudi spy who met two of the hijackers and supported them in the run-up to September 11, the report claims.
Osama Bassnan lived across the street from the hijackers and allegedly received a fake passport and money from Saudi government officials.
An imam at a mosque that was known for its anti-Western views was an accredited Saudi diplomat, the report alleges.
A Saudi interior ministry official stayed at the same hotel, in September 2001, as one hijacker but claimed not to know him.
When the FBI interviewed him, the report says: "The interview was terminated when al-Hussayen either passed out or feigned a seizure requiring medical treatment. He was released from the hospital several days later and managed to depart the United States despite law enforcement efforts to locate and re-interview him."
Two Saudis involved in an alleged "dry run" before the 9/11 attack claimed they were on an expenses-paid trip to the Saudi Embassy in Washington.
CIA and FBI suspicions were not passed on inside the FBI, and the FBI's national office thus remained unaware of the information its regional offices were developing on the Saudis.
The Joint Inquiry admits its information was unconfirmed, that the people named within it may have innocent explanations, and that further investigation was needed.
Later investigation revealed that while some of the allegations did not pan out, Saudi Arabia was nonetheless a source of funds for Al Qaeda.