Hashem Safieddine, a potential successor to his slain cousin Hassan Nasrallah, is one of Hezbollah's most prominent figures and has deep religious and family ties to the Iran.

Safieddine bears a striking resemblance to his charismatic maternal cousin Nasrallah but is several years his junior, aged in his late 50s or early 60s.

A source close to Hezbollah, requesting anonymity as they were not authorised to speak to the media, said the grey-bearded, bespectacled Safieddine was the "most likely" candidate for the party's top job.

The United States and Saudi Arabia put Safieddine, who is a member of Hezbollah's powerful decision-making Shura Council, on their respective lists of designated "terrorists" in 2017.

The US Treasury described him as "a senior leader" in Hezbollah and "a key member" of its executive.

While Hezbollah deputy chief Naim Qassem automatically takes over the Hezbollah leadership after Nasrallah's death, the Shura Council must meet to elect a new secretary-general.

Safieddine has strong ties with Iran after undertaking religious studies in the holy city of Qom.