Before leaving Lebanon for Vienna, Mehlis met with Lebanese Public Prosecutor Saeid Mirza and discussed with him the planned Vienna interrogations.

The French Foreign Ministry expressed "satisfaction" on Tuesday for the interrogations of the five Syrian officers, but declined to comment on Monday's news conference held by "runaway Syrian witness Houssam Taher Houssam," saying it is up to Mehlis to take a stand from Houssam's allegations.

Washington had said late monday that it hopes Syria continues its cooperation and that it is up to Mehlis to carry out the path of investigations.

Meanwhile, reactions to the claims made by Syrian witness Taher Houssam that the UN and Beirut MP Saad Hariri had attempted to coerce his testimony snowballed on Tuesday, with the Lebanese Information Department denying the allegation.

A statement from the department said: "Most of what Houssam said in the press conference is not true, especially regarding the part related to arresting and torturing him."

The statement added that Houssam "visited department headquarters once a few months before the assassination of Hariri, when he was questioned in the case of transporting weapons ... and committing fraud."

It continued to say Houssam "approached the department in June through the Interior Ministry, alleging that he had important information about Hariri's assassination."

However, the department said ensuring the validity of a witness' testimony was not a perfect process, as personnel are "humans not angels.

Ex pro-Syrian politician Walid Jumblatt also denied Houssam's allegations that the two men had met at the UN probe's headquarters in Monteverde, saying: "Mehlis had visited me once on June 28 at my residence in Mukhtara and listened to my statement ... never met with Mehlis afterward."

Jumblatt warned there "is still a strong Syrian intelligence presence in Lebanon," and that the Syrian intelligence apparatus would not cease its attempts "to shake the security in Lebanon."

Lebanese journalist Fares Khashan, also accused Monday of exerting pressure on Houssam to falsify his testimony, said: "Houssam's acting was comic, but it has escaped the Syrian

intelligence apparatus' mind ... that the facts Houssam brought are all made-up illusions."

"I only got to know this person two months ago when he called my office and left his number saying he had information about what he called the masked witness," he said.

Khashan said he first grew suspicious of the witness' motives when he "kept insisting on going on television or having a newspaper interview."

"If he were a witness with such important information the logic says that he has to lay low and not blow his cover," he explained, adding Houssam had visited him at his office several times and kept insisting on "meeting MP Saad Hariri."

However, Khashan said this meeting never occurred as "Hariri was out of the country most of the time."

Houssam had alleged Khashan was Hariri's "personal assistant."

Syria's Foreign Ministry released a statement on Tuesday saying Mehlis' interim report published in October was flawed because it relied on Houssam's "false testimony," in addition to that of another Syrian witness "proven a liar," in reference to Mohammad Zuheir Siddiq.

"Syria, expressing its deep concern over attempts by some to mislead the investigation, points out that seven articles of the report, which was presented by the international committee to the Security Council, are based on Houssam's testimony," the statement said.

A Syrian official was reported by the Syria's SANA news agency as demanding Lebanese authorities to stop the "campaigns of slander against Syria."

The anonymous official said: "We are waiting for the Lebanese judiciary to make a move regarding these extortion campaigns accusing Syria of Hariri's murder."

"Syria expresses is deepest concern of some people's attempt to mislead the investigations," the official added.

According to Lebanese judicial sources, Mehlis will ask the Lebanese judiciary to submit a request to Syria to extradite Houssam for interrogation.

The source further expected Houssam's arrest, "that is if the Syrians accept to hand him over to Lebanon."

Meanwhile, Lebanese Investigating Magistrate Elias Eid has summoned a fourth individual from Sidon for deposition in the Hariri investigation.

Judicial sources identified the individual as Mustafa S., a personal friend of Sidon Mayor Nazih Bizri.

The three others summoned to give their depositions on Thursday were identified as Bizri's sister Roqaya Bizri and family friends Hassan Hashisho and his wife Sokaina.