Omar al-Jaberi, 21, and Sarah al-Jaberi , 20, children of Saad al-Jabri — who has lived in exile in Canada since the rise of bin Salman to power in 2017 — had been detained in March.
Riyadh’s forces also arrested Jabri’s brother in May in another attempt to force the ex-spy chief return home.
In a tweet on Wednesday, Jabri’s other son, Khalid, said his brother-in-law, Salem al-Muzaini, had been summoned on Monday to a Saudi state security office in Riyadh, where he was arrested. He has not been seen or heard from since.
“Salem’s arrest is an obvious attempt to intimidate and blackmail my father,” the tweet said.
“My father filed a lawsuit this month against MBS and two dozen others in US District Court in response to their thwarted efforts to assassinate my father and terrorize my family. Salem’s arrest is a blatant attempt by MBS to interfere with the US judicial process,” said.
Jabri was a senior aide to the deposed former crown prince, Prince Mohammed bin Nayef, and served as the primary Saudi liaison to Western spy agencies.
Bin Nayef, who was always regarded as the senior royal figure closest to western governments, briefly became heir to the throne but was ousted in a palace coup in 2017.
Fearing for his life, Jabri, who was abroad at the time, decided not to return home.
His children were arrested 10 days after the detention of bin Nayef and another senior prince, Ahmed bin Abdulaziz, a brother of King Salman and an uncle of bin Salman, also known as MBS.
Earlier in August, Jabri filed a lawsuit at a US federal court in the District of Columbia against MBS, accusing the top royal of dispatching a hit squad to North America to trap and kill him.
The ex-official, who functioned as a top aide in the Saudi Interior Ministry for years, is reportedly under increased protection by police and private security guards in Canada.
The lawsuit alleges that a team of Saudi agents carrying forensic gear and including forensic experts arrived at an airport in Ontario in October 2018. They tried to enter on Canadian tourist visas but were turned away by Canadian border officials.
Jabri claimed that his close ties with the US intelligence community and deep knowledge of the prince’s activities had turned him into one of the key targets of bin Salman.
Riyadh has already issued Interpol red notices, the highest-level notice, seeking Jabri’s extradition, accusing the former senior intelligence officer of corruption. The international police organization, however, has dismissed the notices as political.
Nevertheless, the Saudi regime has urged other countries to send Jabri back to the Arab kingdom.
In his Wednesday tweet, Khalid said Muzaini had in 2017 been renditioned by Saudi authorities from the United Arab Emirates, but was released in January 2018 after his savings were seized and he was placed under a travel ban.
He called for al-Muzaini’s release as well as his siblings Sarah and Omar, who “have been held incommunicado in Saudi since March because our father rebuffed MBS’s demands that he return to the kingdom.”
It comes two years after the young Saudi crown prince reportedly orchestrated the gruesome assassination of Jamal Khashoggi, a dissident journalist who had been critical of bin Salman’s policies before he was killed at the Saudi consulate in Istanbul in October 2018.
Jabri, a graduate of artificial intelligence from Scotland, is believed to be very well-informed about Saudi Arabia’s top secrets, including the identities of dissidents killed by bin Salman and the place where they have been buried.
Saudi authorities have accused Jabri of involvement in corruption, saying he has been misusing his position to amass a personal fortune. Bin Salman wants him in the kingdom under the pretext of getting the money back.
Some fear that Jabri could eventually be forced back to Riyadh through Washington’s lobbying given the close ties between bin Salman and the US administration.
That could pose the defector to a similar fate to that of Khashoggi.