The United States is intervening in a court case related to an ousted Saudi spymaster, citing protection of its national interests.
Saad al-Jabri, has previously announced that Saudi authorities have tried to assassinate him.
Riyadh’s targeting of the intelligence czar is part of a row between deposed crown prince Mohammed bin Nayef (MBN) and the kingdom's current crown prince Mohammed bin Salman (MBS).
The US has reportedly asked al-Jabri to wait until September 30 before exposing secret information to an Ontario court that could endanger Washington’s national interests.
"Matters involving foreign relations and national security of the United States ...require 'delicate' and 'complex' judgements," government attorney Malcolm Ruby wrote in the letter dated June 29.
The US cannot legally intervene in court cases in Canada but the rare move could prevent al-Jabri from using evidence central to his defense at the court.
His legal battle kicked off after Saudi state-owned companies sued him in a Canadian court, alleging he stole billions of dollars.
The companies alleged that he committed a “massive fraud” totaling at least $3.47 billion.
The Saudi monarchy’s international pursuit of the dissident comes as MBN remains detained in the capital Riyadh.
The administration of US President Joe Biden has come under unprecedented pressure to hold Saudi leaders accountable for targeting of dissident activists abroad.