Mustafa Mughniyeh is the son of Badreddine's sister who was married to Imad Mughniyeh. Mughniyeh senior was assassinated in 2008.
Asharq Al-Awsat is one of the most widespread newspapers in the Arab world, but it is a Saudi publication affiliated with the anti-Hezbollah Sunni axis. Lebanese media has yet to report on any successor to Badreddine.
Intelligence analyst Ronen Solomon has researched Hezbollah's intelligence and security apparatuses and has been following the actions of Mughniyeh's eldest son, said Mustafa has barely been mentioned in the media before.
"The 1980's were the years when (Imad) Mughniyeh spent time at a Quds Force camp near Tehran," Solomon said.
"At the time, he was pursued by foreign intelligence services after he stood behind deadly terror attacks against Western and Israeli targets, which claimed the lives of hundreds of people. In 1982, Mughniyeh opened a security guard company in Lebanon and married his cousin Saadi Badreddine – the sister of Mustafa Badreddine, who was appointed Hezbollah's military commander," Solomon told Ynet.
During those years, Mughniyeh had tried to secure the release of his brother-in-law Mustafa Badreddine, who was arrested following the attack on the American Embassy in Kuwait in 1983.
"In January 1987, when Mustafa was still in jail in Kuwait, Imad Mugniyeh's eldest son was born. He named him Mustafa, after his wife's brother – it's clear this wasn't a coincidence," Solomon said.
"During that same year, Mughniyeh senior's parents came for a visit in Teheran and were photographed with the whole family, apparently to mark Mustafa's birthday, who was born that year. (Mustafa) was not included in the picture and until today there is not one single photo of him," he added.
A year later, Badreddine managed to get out of jail in Kuwait and arrived at the Iranian Embassy, while taking advantage of the chaos following the invasion of Kuwait by then-Iraqi President Saddam Hussain.
According to Solomon's investigation, while Mughniyeh senior was in charge of Hezbollah's military and operational activities, Mustafa had been training in Iran: "In 2005, he was 18 years old – the age when one completes basic military training in Hezbollah and is sent to specialize in a certain field. At the same time, Mustafa began joining his father on operational missions, and hence received an informal education.
"Meanwhile, the relationship between Mustafa Mughniyeh's mother, Saadi, and her brother, Mustafa Badreddine was maintained at all times. Proof for that is shown in the findings from the investigation on the assassination of Rafik al-Hariri, the former prime minister of Lebanon, which included documentation of thousands of conversations between the two. The history of their relationship ended up playing an important role after Imad Mughniyeh's assassination."
After the death of Mughniyeh senior, an interesting process began to unfold. As Jihad Mughniyeh, the youngest son, was becoming more publicly known, the oldest son Mustafa continued to stay a mystery, with few mentions in the media.
A few months after the assassination of Mughniyeh senior, it was reported that Mustafa became a father to a son in Beirut who they named Imad after his deceased grandfather.
Four years later, during a broadcast by the Lebanese satellite TV station Al Manar in honor of the anniversary of Mughniyeh's death, Mustafa's son was interviewed wearing a military uniform. Imad junior was accompanied by the parents of Imad Mughniyeh senior, but his father Mustafa was nowhere to be seen.
Ibrahim Al-Amin, an editor of a Hezbollah journal, said in January that the rest of the family had expected Mustafa, the eldest son, to publicly announce his father Imad's death. However, Mustafa answered that he was not the right man for the task and instead the task fell on young Jihad, who, up until then, was taken less seriously compared to Mustafa.
Meanwhile, Mustafa became the protégé son and confidant of his father's successor, his uncle Mustafa Badreddine. Mustafa Mughniyeh is mentioned as having a role in coordinating the movements of Hezbollah leaders in Lebanon, Syria and Iran, and entrusted with their personal security. Furthermore, he is said to provide vehicles for his uncle Badreddine and his personal security.
"As history shows, whoever went up the ladder to participate in secret Hezbollah operations, first held positions related to the personal security of various key members of the organization. It can be presumed that Mustafa's identity has been kept mysterious, as opposed to his brother, to ensure that in the future he will be included in secret missions, such as those carried out by the 910 unit (Hezbollah's unit in charge of overseas attacks), led by his uncle Mustafa Badreddine."
In August 2011, Mustafa's name emerged in connection to a mysterious explosion that took place in a southern suburb of Beirut, known as a Hezbollah stronghold. In the beginning, it was reported that the explosion was intended to target Samir Kuntar - a member of the Palestine Liberation Front, who was convicted of murdering the Israeli Haran family in a terrorist attack in 1979.
Later on, it was believed that it was actually Mustafa Mughniyeh who had been the target of the explosion. The building that was blown up was used by Mughniyeh as an office. The explosion resulted in the death of Mustafa's security guard and another individual was wounded.
During that time, Hezbollah began to believe that a foreign agent had infiltrated their security apparatus and that Mustafa Mughniyeh's name had been leaked along with several other Hezbollah members in a 2011 report on French newspaper Le Figaro. In response to that report, a Facebook page covering Hezbollah's fighting in Syria quoting sources close to the terror organization as admitting for the first time that Mustafa was operating in Hezbollah's ranks against Israel and the rebels in Syria.
It is possible that the foreign agent who had operated against the organization was high-ranking Hezbollah official Mohammad Shorba - who is now known to have worked with the Mossad and CIA during those years.
Saudi media recently reported that Mustafa took over command of Hezbollah's operations in the Golan Heights after the assassination of his younger brother Jihad Mughniyeh in an airstrike in January 2015 attributed to Israel.