Saad al-Jabri, a veteran figure in the Saudi government, was the alleged target of the assassination plot, according to a lawsuit filed in a US court on Thursday.
Mr Jabri was a long-time aide to Prince Mohammed bin Nayef, who was ousted as heir to the throne in a 2017 palace coup.
He fled to Canada at the time, via Turkey, and has been under private security protection in Toronto ever since.
In the 107-page lawsuit filed against Mohammed bin Salman, widely known as MBS, Mr Jabri said the crown prince “dispatched a hit squad” to Canada in October 2018.
“(A) team of Saudi nationals travelled across the Atlantic Ocean from Saudi Arabia ... with the intention of killing Dr Saad,” said the lawsuit, which seeks punitive damages in an amount to be determined at trial.
Mr Jabri says he was targeted due to “damning information” he possesses, including details on alleged corruption and a group of mercenaries, called the Tiger Squad, who have been linked to the murder of journalist Jamal Khashoggi.
“Few places hold more sensitive, humiliating and damning information about defendant bin Salman than the mind and memory of Dr Saad – except perhaps the recordings Dr Saad made in anticipation of his killing,” the lawsuit says.
“That is why defendant bin Salman wants him dead, and why defendant bin Salman has worked to achieve that objective over the last three years.”
The hit squad sent to kill Mr Jabri comprised of members of the Tiger Squad, and were carrying two bags of forensic tools when they were stopped by Canadian border agents, the lawsuit added.
It says the men “attempted to enter Canada covertly, travelling on tourist visas” and pretending not to know each other. Suspicious border agents found a photo showing several of the men together, “revealing their lie and thwarting their mission”.
The alleged incident took place less than two weeks after Mr Khashoggi’s murder in Saudi Arabia’s Istanbul consulate.
Mr Jabri claims MBS has made repeated efforts to return him to Saudi Arabia, even sending private messages, including one that read: “We shall certainly reach you.”
His family say that the Crown Prince has detained two of his adult children and his brother to try to force his return.
Mr Jabri, who served as a key go-between for MI6 and other western spy agencies in Saudi Arabia, said he filed the lawsuit in the US in part because the alleged plot against him “involved substantial conduct inside the United States”.
Canada’s federal minister of public safety Bill Blair said he could not comment on the case but said the government was “aware of incidents in which foreign actors have attempted to monitor, intimidate or threaten Canadians and those living in Canada”.
The Saudi government could not be reached for comment on Thursday.