Anas Sharkas, also known by his nom de guerre of Abu Ali Shishani, vowed to kidnap Lebanese women and children if his own wife and children are not released soon, in a video posted online.
Sitting beneath an ISIS flag, Shishani, who was previously thought to be an affiliate of the al-Qaeda-linked Nusra Front, urged Sunni Muslims in Lebanon to rise up against authorities and target Shiites in the country.
"I call on you, Sunnis, to rise up in unity. Our wives and men are in prisons. They took my wife and children and had no right to do so," he says in the video, according to Lebanon's The Daily Star newspaper.
"All your [Shiite] wives, children and men are legitimate targets now," he said. "I will start taking action very soon to take captive women and children."
The terrorist leader denied that Beirut authorities hold Baghdadi's wife, saying the woman is instead his spouse, Ola Mithqal al-Oqaily. She was arrested with his two children in the northern city of Tripoli earlier this week, he said.
The video added to the confusion surrounding the identity of a woman captured in northern Lebanon while travelling with her children on a fake ID in November.
Lebanese authorities initially said they were the wife and child of the ISIS leader Baghdadi and separately announced the arrest of Shishani's family members.
Earlier this week, however, Iraq's Interior Ministry denied that the woman, named as Saja al-Dulaimi, was a wife of Baghdadi, claiming she was the sister of a terror suspect being held in Iraq.
Later, Lebanon's interior minister corrected his government line on the issue, saying that Dulaimi and Baghdadi were no longer married.
"Dulaimi is not Abu Bakr al-Baghdadi's wife currently," Interior Minister Nohad Machnouk told Lebanese channel MTV. "She has been married three times: first to a man from the former Iraqi regime, with whom she had two sons," he explained.
"Six years ago she married Abu Bakr al-Baghdadi for three months, and she had a daughter with him. Now, she is married to a Palestinian and she is pregnant with his child."
Machnouk said that a DNA test confirmed that the girl travelling with Dulaimi at the time of her arrest was indeed Baghdadi's daughter.
Beirut is currently negotiating the release of about 20 soldiers and police held hostage by terrorist in Syria and could use the women and children as bargain chips.