The UN inquiry probing the murder of former Lebanese premier Rafiq Hariri demanded Monday to interview Syrian president Bashar al-Assad after a former deputy implicated his regime in the assassination.
An inquiry spokeswoman said UN investigators were also looking to talk to Foreign Minister Faruq Shara as well as former vice president Abdel Halim Khaddam, who made the explosive allegations after fleeing into exile in Paris.
"We asked to interview Assad, Shara and others. We are awaiting an answer (from the Syrian authorities)," said inquiry spokeswoman Nasrat Hassan.
She added that the commission wanted to meet Khaddam "as soon as possible" after his comments in an interview with Al-Arabiya television in which he accused Assad of threatening Hariri just months before his murder.
"This is the immediate effect of Khaddam's bombshell as he was a pillar of the Syrian regime," said Lebanese political scientist Joseph Bahout. "Mr Assad will find it difficult to refuse receiving the commission."
The request for an interview presents Assad with yet another delicate choice - whether to risk losing face by being interrogated by UN investigators or take a stand and see his country slip into international isolation.
Khaddam quoted Assad as telling Hariri during a meeting in Damascus: "I will destroy anyone who tries to hinder our decisions."
"We must await the results of the investigation, but no Syrian security service could take such a decision unilaterally," added Khaddam, long the architect of Syria's military and political domination of neighbouring Lebanon.
According to the An-Nahar daily, Khaddam's declarations were "identical to the commission's conclusions".
Simon Karam, a former Lebanese ambassador to the United States, told AFP that Khaddam's comments had given the inquiry a push forward at a time when its pace was stumbling due to Syria's "manipulations."
Hariri's son and political heir Saad hailed Khaddam's comments as "historic testimony".
Khaddam was slung out of the ruling Baath party for making the comments, while the Syrian government said in an official newspaper announcement it will try Khaddam on high treason charges and investigate him for corruption.
It remains to be seen whether Assad and Shara will agree to the demands to interview them, having rebuffed previous requests from the previous inquiry chief, Detlev Mehlis.
Shara, who was accused by the United Nations of misleading the inquiry in a written response, has in the past declared himself ready to meet the commission while travelling in Europe.
In an interview with CNN in October, Assad vehemently rejected any notion he had played a personal role in the Hariri assassination, saying he found out about the murder by watching the news.
In late March, Syria also denied a report from a UN fact-finding mission that Assad had threatened both Hariri and Druze leader Walid Jumblatt if they opposed the policies of Damascus.
However five Syria did agree to allow five security officers, including its former head of intelligence in Lebanon Rustom Ghazale, to be interrogated in Vienna in November. It also interviewed around a dozen officials in Syria in September.
Mehlis's first report in October contained witness testimony implicating the very heart of the Assad family in the assassination, namely Assad's brother Maher Assad and his brother-in-law Assef Shawkat.
Belgian prosecutor Serge Brammertz is expected to be named this month as the German magistrate's successor.
The murder of Hariri, a billionaire businessman and five-time prime minister, plunged Lebanon into political turmoil and heightened international pressure on Syria to end its 29-year military presence in its smaller neighbour last April.
Khaddam, 73, first announced his shock resignation as vice president at a Baath party congress in June.