The Lebanese army detained a wife and a son of ISIL leader Abu Bakr Al Baghdadi as they crossed from Syria in recent days, officials said on Tuesday.
The two were arrested more than a week ago at an illegal border crossing with Syria, Beirut-based Al Mayadeen TV said. The detained woman is Syrian and Baghdadi’s second wife, Al Arabiya TV said.
They were detained in coordination with "foreign intelligence apparatus”, a Lebanese newspaper reported.
It said she had been travelling with a fake passport accompanied by one of her sons, reportedly about eight years old.
ISIL has seized wide areas of Iraq and Syria, Lebanon’s neighbour to the east, declaring a "caliphate” over the territory it controls.
Investigators were questioning her at the headquarters of the Lebanese defence ministry.
Lebanese security forces have waged a crackdown on ISIL sympathisers in the country and the intelligence services have been extra vigilant at the border crossings.
In the last few months, they have arrested a number of Islamic militants suspected of staging attacks to expand the militant group’s influence in the country.
A US-led alliance is seeking to roll back ISIL’s territorial gains in Iraq and Syria.
US president Barack Obama has vowed to "degrade and ultimately destroy” Baghdadi’s group, which is seeking to reshape the Middle East according to its radical vision of Islam.