``If there is a person who is involved then he must be held accountable, but at the same time to say that a Syrian person is guilty there must be evidence,'' Assad said in an interview with Russia's channel 2 television station.

Assad was answering a question on whether he would arrest any official, even relatives, if indicted by a United Nations inquiry into the Feb 14 murder of Hariri, Syria's former ally.

In October, an initial report by a U.N. probe into the assassination implicated Syria and named Assad's brother-in-law Major General Asef Shawkat in its account of a testimony by an unidentified witness.

In November, a Syrian witness, Hosam Taher Hosam, said he fled Lebanon after giving false testimony about Shawkat under pressure from anti-Syrian Lebanese officials and said that he was the witness quoted in the report.

``The issues is not that of (certain) names, close or not,'' he said. ``Whoever in Syria is proven linked to the assassination then according to the Syrian law that person is regarded a traitor and the penalty of a traitor is extremely severe.''

But Assad, in the interview aired by the Syrian television late on Sunday, said legal action against any Syrian can only be based on solid proof and not ``politicized'' conclusions.

Chief U.N. investigator Detlev Mehlis said in remarks published on Saturday that his committee will summon more Syrian witnesses in the next few days. He did not name them.

The remarks of Mehlis raised expectations that he might ask to question more senior officials, including inner-circle top brass, political sources in Lebanon said.

Mehlis is due to present his findings to the U.N. Security Council on December 13.

Assad voiced hope the inquiry would be ``professional, fair, objective and thorough ... If it is professional then it would serve Syria directly because we have great confidence, almost absolute if we are not to say absolute, in Syria's innocence.''

To avert a showdown with the world body, Syria has allowed U.N. investigators to question five officials.

Neither Syria nor the U.N. has identified the officials questioned, but diplomatic sources say they included Lt. Gen. Rustom Ghazali, Syria's former intelligence chief in Lebanon and his aide, Jamae Jamae.

Syria says its cooperation with the inquiry should prevent any punitive action. The Security Council has warned unspecified action against Damascus if it failed to cooperate. (Reuters)