French police have arrested a key Syrian witness in a United Nations probe of the assassination of former Lebanese Prime Minister Rafik Hariri.

Police say Muhammad al-Siddiq was arrested Sunday outside Paris, and is expected to be extradited to Beirut in the near future.

Lebanese media reports say Mr. al-Siddiq has claimed to have participated in a meeting of Lebanese security officials who allegedly designed the assassination plan. Syrian officials claim he is unreliable.

A report from the U.N.-appointed prosecutor probing the assassination is expected to implicate Syrian officials in the February 14 bombing that killed Mr. Hariri and 20 others in Beirut.

U.N. Secretary-General Kofi Annan says he will wait to read a report due next week from prosecutor Detlev Mehlis before deciding whether to extend the probe to December, as requested last week by Lebanese lawmakers.

Some information for this report provided by AP, AFP and Reuters.