A Middle East Airlines flight, at Rafic Hariri International Airport, Beirut, Lebanon. WIKIMEDIA COMMONS
Hezbollah had told Lebanese security forces that a Russian citizen "was recruited by the Israelis for a reconnaissance mission of their headquarters in the southern suburbs of Beirut and south Lebanon", the official told AFP.
Security forces arrested him around two weeks ago at Beirut airport while he was trying to flee with his wife and child, the official said.
It came after Hezbollah told security forces that the suspect had tried to break into an apartment in Beirut's southern suburb, a stronghold for the group.
Following his arrest he was interrogated at the general security department and then referred to military prosecutors who are now in charge of the investigation.
On Friday, the interim chief of Lebanon's General Security agency Elias al-Baysari said authorities had arrested "a two-person network with ties to the enemy (Israel) at Beirut airport, and who were tasked to carry out operations" in Lebanon.
"We interrogated them and referred them to the competent military judiciary," he added, without providing details on the nationality of the detained.
On Saturday, the Russian embassy in Beirut said it was "aware" of the arrests and "taking the necessary steps to clarify the details of the circumstances", according to state-run news agency RIA Novosti.
Lebanon technically remains at war with Israel and forbids citizens from having any contact with Israel or travelling there.
Israel and Hezbollah fought a 33-day war in Lebanon in 2006.
The number of people arrested for allegedly collaborating with Israel has signficantly jumped since the country's economy collapsed in late 2019, security officials had previously told AFP.