Sabih al-Masri, a Palestinian billionaire and the chairman of Jordan's largest lender Arab Bank, was detained in Saudi Arabia for questioning after a business trip to Riyadh, family sources and friends said on Saturday.

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They said Masri, a Saudi citizen and Jordan's most prominent businessman with holdings in hotels and banking, was arrested after heading to the Saudi capital last week on a trip to chair meetings of companies he owns.

He had cancelled a dinner on Tuesday that he had invited friends and leading businessmen to attend on his return.

Open gallery view A picture taken on August 16, 2014 shows the Arab Bank's main offices in the Jordanian capital, Amman. Jordan's Arab Bank went on trial on August 15, 2014 in New York accused of aiding terror by trans Credit: AFP PHOTO/KHALIL MAZRAAWI

Masri could not be reached for comment. The Saudi authorities did not respond to requests for comment.

Confidants said Masri had been warned not to travel to Saudi Arabia after mass arrests last month of Saudi royals, ministers and businessmen in the biggest purge of the kingdom's affluent elite in its modern history.

"He has been answering questions about his business and partners," said a source familiar with the matter who did not elaborate nor confirm he was held. Another family source said he was detained.

Masri, who originally comes from a prominent merchant family from Nablus in the Israeli-occupied West Bank, amassed a fortune from partnering with influential Saudis in a major catering business to supply troops during the U.S.-led military operation to retake Kuwait from Iraq in the 1991 Gulf War.

Local media reports that he was detained since Thursday sent shockwaves across Jordan where Masri's multi-billion dollar investments are a cornerstone of the economy and employ thousands.

Masri was elected chairman of Arab Bank in 2012 after the resignation of Abdel Hamid Shoman whose family had founded the bank in Jerusalem in 1930.

He is also the leading investor in the Palestinian territories with a large stake in Paltel, a public shareholding company, which is the largest private sector firm in the West Bank.

Masri's family ranks among the wealthiest of Palestinian families, with majority holdings in real estate, hotels and telecommunications firms set up in the territories after a self-rule agreement with Israel in 1993.

Masri is the cousin of Munil al-Masri, considered the world's richest Palestinian, who runs an investment company that controls the West Bank's telecommunications sector, and has holdings in industry, agriculture, tourism and in banks, as well as founding the Palestinian Security Exchange.

Last year, a consortium of Arab and Jordanian investors led by Masri bought a 20 percent stake in Jordan’s Arab Bank Group for $1.12 billion from Oger, a holding company owned by Lebanon’s Hariri family.

Masri led negotiations to buy stake after the family of Saudi Arabia’s Fawaz Alhokair dropped a $1.1 billion offer.

The stake held by Oger Middle East Holding, which is owned by the family of Lebanese Prime Minister Saad al-Hariri, who recently resigned from his post while in Saudi Arabia, only to return to Lebanon and rescind it amid reports he was held in Riyadh against his will. Hariri's arrest followed a purge by the Saudi crown prince against members of his family that also saw prominent Saudi business leaders held.