BEIRUT (NYTIMES) - As Crown Prince Mohammed bin Salman of Saudi Arabia sidelined rivals to consolidate power a few years ago, a former Saudi intelligence official feared that he would end up in the prince's sights and slipped out of the kingdom.

The crown prince has been trying to get him back since, first asking the former official, Saad Aljabri, to come home for a new job, then trying unsuccessfully to have him extradited on corruption charges through Interpol, according to text messages and legal documents reviewed by The New York Times.

"You are involved in many large cases of corruption that have been proven," Crown Prince Mohammed wrote to the former official in September 2017. "There is no state in the world that would refuse to turn you over."

But Interpol questioned the Saudi commitment to due process and human rights in the kingdom's handling of corruption cases and deemed the Saudi request for Aljabri politically motivated, a violation of the organisation's rules, according to Interpol documents.

So it removed Aljabri's name from its system.

The text messages and documents reviewed by the Times, which have not been previously reported, shed new light on how far Crown Prince Mohammed has reached to exert control over Saudis he fears could subvert him.

The struggle has accelerated this year.

In March, Saudi Arabia detained two of Aljabri's adult children and his brother, prompting accusations by relatives and US officials that they were being held hostage to secure Aljabri's return.

And last week, the kingdom's state-controlled news media seized upon an article in the The Wall Street Journal that cited unidentified Saudi officials accusing Aljabri of misspending billions of dollars in state funds to enrich himself and relatives.

One Saudi newspaper published a wanted poster with Aljabri's face on it, part of an apparent effort to tarnish his reputation in the kingdom.

The revelations come amid concerns about the health of Crown Prince Mohammed's father, King Salman, whose death could put the prince in charge of Saudi Arabia for decades.

The king, 84, was hospitalised over the weekend and underwent successful gall bladder surgery, Saudi state media reported on Thursday (July 23).

Since his father became king in 2015, Crown Prince Mohammed, 34, has taken charge of military, economic and social policies while targeting critics and foes with travel bans, detentions and lawsuits.

These increasingly authoritarian tactics caught global attention when Saudi agents killed Jamal Khashoggi, the dissident Saudi writer, inside the Saudi consulate in Istanbul in 2018, bringing widespread condemnation.

The Saudi moves against Aljabri have drawn attention in Washington, where many officials considered him a valuable intelligence partner.

In a letter to President Donald Trump this month, four senators referred to Aljabri as "a close US ally and friend" and said the United States had "a moral obligation to do what it can to assist in securing his children's freedom."

TEXT MESSAGES

Officials at the Saudi Embassy in Washington did not respond to requests for comment about the text messages between Crown Prince Mohammed and Aljabri, the Saudi Interpol request or the kingdom's corruption allegations.

The Times reviewed scores of text messages between the two men provided by a law firm working for Aljabri, Norton Rose Fulbright Canada, and Interpol documents informing Aljabri of its decision about the Saudi request against him.

Aljabri's rise and fall were tied to his association with Crown Prince Mohammed's primary rival for the Saudi throne, Prince Mohammed bin Nayef, who headed the Interior Ministry and became crown prince in 2015.

A linguist with a doctorate in artificial intelligence, Aljabri became a top official at the ministry, which handles security and counterterrorism, putting him in regular contact with US diplomats and officials from the CIA.

Many have praised his professionalism.

"Aljabri is really smart, and he has encyclopedic knowledge," said Douglas London, a former officer in the CIA's Clandestine Service and nonresident scholar at the Middle East Institute in Washington. "He lived up to his word, he did not overpromise, and he delivered."

But Aljabri's star fell as Crown Prince Mohammed's rose.

Aljabri was dismissed by royal decree in 2015.

In 2017, Aljabri began to fear that Crown Prince Mohammed intended to replace Mohammed bin Nayef as crown prince and target his domestic allies, so Aljabri left the kingdom, settling in Turkey.

CHILDREN UNDER HOUSE ARREST

On June 18 of that year, Crown Prince Mohammed texted him, asking Aljabri to return to help solve an unspecified issue with Mohammed bin Nayef, according to translated versions of texts provided by Aljabri's law firm.

"I want to explain to you what has happened recently and come to an agreement with you about a strategy to solve all these difficulties," Crown Prince Mohammed wrote.

Aljabri replied that he was "prepared to accept whatever you command."

Crown Prince Mohammed said he wanted the three men to meet so they could "reconcile and everything can return to the way it was."

On June 20, Aljabri said he could not return to Saudi Arabia immediately because of medical treatment.

Crown Prince Mohammed said he had only summoned him because he was "in dire need of your assistance."

The next day, however, Crown Prince Mohammed ousted Mohammed bin Nayef as crown prince and took his place.

Mohammed bin Nayef was placed under house arrest, and two of Aljabri's children - Sarah, who was 17 at the time, and Omar, who was 18 - were barred from leaving Saudi Arabia.

Pleas by Aljabri for his children to be released were ignored.

Some three months later, Crown Prince Mohammed texted him, threatening to have Aljabri arrested abroad.

With the danger now clear, Aljabri moved from Turkey to Canada, according to his son, Khalid Aljabri, a cardiologist also based in Canada.

To try to force him home, Saudi authorities filed a notice with Interpol, the international police organisation, asking other nations to help with Saad Aljabri's extradition, according to Interpol documents.

INTERPOL HELP SOUGHT

But instead of filing for a Red Notice, which acts like an international arrest warrant, the Saudis filed a diffusion, which Interpol describes as a less formal way for Interpol members to request help from other nations.

Aljabri confirmed that his name was in the Interpol system in December 2017, when his wife and other relatives were barred from flying from Turkey to Canada because their party contained another Saad Aljabri: Aljabri's infant grandson and namesake, Khalid Aljabri said.

The family nonetheless managed to get to Canada via the United States and appealed the inclusion of Saad Aljabri's name in the Interpol system. They won in July 2018, according to an Interpol document about the decision.

The Interpol commission wrote that the anti-corruption committee that oversaw that crackdown was "part of a political strategy by MBS to target any potential political rival or opposition."

The kingdom soon found other ways to pressure Aljabri. In March, his two adult children who had been barred from leaving the kingdom were arrested in their Riyadh home.

In May, Aljabri's brother was arrested.

None have contacted their relatives since, Khalid Aljabri said.

"The Saudi royal family is holding Sarah and Omar Aljabri as hostages," Sen. Patrick Leahy, D-Vt., wrote on Twitter this month with the letter from him and three other senators to Mr Trump. "For a government to use such tactics is abhorrent. They should be released immediately."