Lebanese security authorities arrested a second employee at state-owned mobile telecom firm Alfa on suspicion of spying for Israel, security sources said on Thursday.
They described Tareq Raba'a as a telecoms engineer and said he was "more dangerous" than Charbel Qazzi, another employee who was arrested last month and was referred to a military court this week. If convicted he could face the death penalty.
Security sources said Raba'a was arrested on Monday and was under investigation.
They said he had been an employee at Alfa since 1996 and began working for Israeli intelligence in 2001, adding that he used to leave Lebanon twice a month and every time he would bring back at least $10,000 in cash.
The arrests are part of a broad espionage investigation which has led to more than 50 arrests since April last year. Israel has not commented on the detentions.
Lebanon has described the arrests as a major blow to Israel's intelligence gathering in the country and said many suspects helped identify targets in Lebanon that Israel bombed during its 2006 war with the militant group Hezbollah.
Qazzi's arrest last month shocked the country and prompted debate on how deeply Israel had infiltrated Lebanon's telecoms and security sectors.
President Michel Suleiman, who under Lebanese law must sign a death sentence before it is carried out, has called for severe punishment for spies. The cabinet also agreed that death sentences handed down to spies for Israel should be carried out.
Lebanese courts have until now handed down what were widely seen as light sentences against nationals who worked with Israeli occupation forces and their local militias. Israel ended its 22-year occupation of mainly Shi'ite south Lebanon in 2000.
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