Lebanese authorities have detained a senior member of a Christian party allied with the Shia Hezbollah group on suspicion of spying for Israel.

"Fayez Karam of (retired) General Michel Aoun's Free Patriotic Movement is being held for questioning for his possible involvement
in espionage" on behalf of Israel, a source close to the party said on Tuesday on condition of anonymity.

Al Jazeera's correspondent, reporting from Beirut, said the Free Patriotic Movement leadership had confirmed the arrest.

Karam, 64, was a general in the Lebanese army during the country's 1975-1990 civil war but quit the military after Aoun, who was army chief and who fought Syrian troops near the end of the war, went into exile in France.

The suspect was the third to be detained over the past week on suspicion of spying for Israel.

A high-ranking army officer and a state telecom operator employee were arrested earlier in week as a result of different security operations.

Spy crackdown

More than 70 people have been arrested on suspicion of spying for the Israel's Mossad intelligence agency since April 2009, when the government launched a nationwide crackdown on suspected agents.

The arrests include members of the security forces and telecom employees.

Michel Sleiman, the Lebanese president, 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.

Three men have since been sentenced to death, including one found guilty of aiding Israel during its devastating 2006 war with Hezbollah.