Rasa News Agency reports - "Majed al-Majed, who suffered from kidney disease and was in poor health, has died," the source said on condition of anonymity on Saturday.
A Lebanese army general also confirmed the death of the senior al-Qaeda commander.
Majed, who was arrested on Monday, was the ringleader of Abdullah Azzam Brigades, an al-Qaeda offshoot that operates throughout the Middle East.
The group is responsible for the twin bomb attacks against the Iranian Embassy in the Lebanese capital on November 19, 2013.
The back-to-back blasts killed at least 25 people, including Iran’s Cultural Attaché to Beirut Hojjatoleslam Ebrahim Ansari, and left more than 160 injured.
Saudi ambassador to Lebanon, Ali Saeed Asiri, had previously said that Lebanon should extradite Majed to the kingdom in case his identity is confirmed.
On December 3, Hezbollah Secretary-General Seyyed Hassan Nasrallah said Saudi Arabia was behind the bombings on the Iranian Embassy, saying he had no doubt that the Saudi intelligence agency has close links with the terrorist Abdullah Azzam Brigades.
The group “is a bona fide group that has a Saudi emir and its leadership is directly linked to Saudi intelligence,” Nasrallah stated.
Majed, a high-profile terrorist wanted by many countries, had earlier traveled to Syria to pledge allegiance to the notorious al-Nusra Front, which is fighting against the Syrian government.