Beirut: Lebanon has detained a Syrian suspect in the killing of anti-Syrian lawmaker and newspaper magnate Gebran Tueni, judicial sources said on Tuesday.

Military magistrate Rashid Mezher ordered the arrest of Abdul Kader AbdelKader, a scrap dealer, after questioning him and two other Syrians who have since been released, the sources said on condition of anonymity.

A judicial official said authorities were still listening to testimony of a number of witnesses in the Tueni assassination. He said Mezher also had issued arrest warrants for other unidentified suspects on Tuesday.

The December 12 car bomb killing of Tueni was the third political murder in Lebanon since the February 14 assassination of former Prime Minister Rafik Al Hariri plunged the country into months of turmoil.

Abdul Kader was present near the site of Tueni's killing in a Christian suburb of Beirut and made mobile phone calls before and after the explosion, which also killed Tueni's driver and bodyguard, the sources added without elaborating.

An ongoing UN investigation has implicated senior Syrian officials and their Lebanese allies in Hariri's murder, echoing feelings among many Lebanese who also blame Damascus for the other political killings.

Syria denies any role but Hariri's assassination sparked mass protests in Beirut that forced it to bow to world pressure and withdraw its troops from Lebanon in April after 29 years.

Detlev Mehlis, the outgoing chief of the inquiry, said earlier this month Hariri's murder was probably linked to other politically-motivated crimes.

The 48-year old Tueni was a fierce critic of Syria's grip on Lebanon, publishing his biting editorials on the front-page of his An-Nahar newspaper, Lebanon's leading daily.

Damascus has said that it is the target of an international witch-hunt over its alleged failure to prevent militants crossing into Iraq and support for what Washington calls "terrorist groups" such as Lebanon's Shiite militant group Hezbollah.

The UN Security Council earlier this month turned down the Lebanese government's request to broaden the Hariri probe to include other bombings, offering instead the commission's technical assistance.

The judicial official said authorities were still listening to testimony of a number of witnesses in the Tueni assassination. He said Mizher also had issued arrest warrants for other unidentified suspects on Tuesday.