Lebanon's president called on Saudi Arabia on Saturday to clarify why Lebanese Prime Minister Saad al-Hariri could not leave the kingdom and return home.
A senior Lebanese official said President Michel Aoun told foreign ambassadors that Hariri, who resigned suddenly while in Saudi Arabia a week ago, had been "kidnapped" and should benefit from immunity as prime minister.
"Lebanon does not accept its prime minister being in a situation at odds with international treaties," Aoun said in a statement.
Hariri's resignation, which caught even his close aides by surprise, has plunged Lebanon into crisis. It has thrust the country back to the forefront of a power struggle between Sunni Saudi Arabia and Shia Iran – a rivalry that has wrought upheaval in Syria, Iraq, Yemen, and Bahrain.
Aoun added that anything Hariri has said or may say "does not reflect reality" due to the mystery surrounding his status since his shock resignation in a broadcast from Saudi Arabia.
Lebanese authorities believe Riyadh is holding Hariri, two top Lebanese government officials, a senior politician close to Hariri and a fourth source have said.
French President Emmanuel Macron, who made an unscheduled visit to Riyadh this week, phoned Aoun on Saturday to discuss the crisis, after comments by a French official that suggested Paris believed Hariri may not be a free man.
Riyadh says Hariri is free and had decided to resign because Iran's Lebanese ally, Hezbollah, was calling the shots in his coalition government.
Western countries have looked on with alarm at rising regional tensions.
The resignation of Hariri, a business tycoon whose family made their fortune in Saudi Arabia, happened at the same time as a wave of arrests of Saudi princes and businessmen accused of corruption by Crown Prince Mohammed Bin Salman.
When he went [to Saudi Arabia] he was asked to stay there and ordered to resign. They ordered him to read his resignation statement and he has been held under house arrest since.
Two US officials said the Saudis, led by Crown Prince Mohammed, had "encouraged" Hariri to leave office.
The fourth source said: "He is under controlled movement by the Saudis, limited movement."