A former Syrian minister who defected this year said Saturday that it was "well-known" that Vice President Faruq al-Shara had tried to leave and was under house arrest.
The comments by former deputy oil minister Abdo Hussameddin came after the regime in Damascus denied opposition claims that Shara, the most senior Sunni Muslim official in President Bashar al-Assad's Alawite-led regime, had defected.
"Shara's position is well known. He has been trying to leave Syria," he told pan-Arab television Al-Arabiya.
"But there are a series of circumstances that prevent him from leaving, especially the fact that he has been under house arrest for some time," he said, adding that top level officials in Syria were being kept under surveillance.
Syrian state television had earlier quoted a statement from Shara's office saying: "Mr Shara has never thought about leaving the country or going anywhere."
Shara did not himself appear on the television.
Hussameddin defected in March, one of a string of defections that has included former prime minister Riad Hijab and high profile General Manaf Tlass -- a childhood friend of Assad.
French Foreign Minister Laurent Fabius said earlier this week he had information that Assad's regime would be rocked by more "spectacular" defections soon.