Lebanese media reported Thursday that Hilmi Moussa, Israel-affairs reporter for local newspaper A Safir, was being held in Syria since Monday and that former Balad chairman Azmi Bishara was trying to secure his release.
Moussa was apparently detained on suspicion of contacting an Israeli agent.
According to several reports, Syrian security forces arrested Moussa, a journalist of Palestinian extraction, while he was making a speech in Damascus.
A Lebanese Web site identified with anti-Syrian elements in the country reported that Bishara - suspected of spying for Hizbullah during the Second Lebanon War - had arrived in Syria in an effort to secure Moussa's release.
Israel Radio reported that Damascus has so far not responded to the allegations.