Saudi Crown Prince Mohammed bin Salman has rejected allegations that he sent a hit squad to kill an exiled Saudi former intelligence officer.
In a lawsuit filed in a US court, Saad al-Jabri has claimed that the assassination attempt took place in Canada, where he fled three years ago.
He says Mohammed bin Salman wanted him dead because he knew too much.
The crown prince - regarded as Saudi Arabia's de-facto ruler - said Mr Jabri was trying to conceal his own crimes.
He pointed out that he is immune from prosecution as a head of state. Serving foreign leaders are also normally immune from civil suits in the US.
However Mr Jabri is suing the crown prince under of the Alien Tort statute and the 1991 Torture Victim Protection Act, which allow foreign nationals to file complaints in the US over alleged human rights abuses.
Lawyers for the 35-year-old prince said Mr Jabri's complaint was "steeped in drama, including an introduction that likens the crown prince to one of Shakespeare's greatest villains".
"But, regardless of its merits as literature, the complaint fails as a legal pleading," they said.