Like his relative, Hashem Safieddine wears the black turban, indicating that he is a direct descendant of the Muslim prophet Muhammed.
The family connection, and the physical resemblance to the revered Nasrallah within the movement, is believed to facilitate his cousin's potential path to the position of power.
Safieddine, who is said to be in his 60s, is theologically educated and is currently responsible for Hezbollah's education system and financing.
Terror-listed
Despite his areas of responsibility primarily concerning the group's political activities, he is also heavily involved in the military. He sits on the so-called "Jihad Council", which oversees military operations, and frequently makes statements calling for struggle and solidarity with Palestinian warriors.
Most recently, in June, at the funeral of the high-ranking Hezbollah commander Taleb Sami Abdullah, Safieddine delivered a speech threatening escalation and revenge against Israel.
The USA has had him on its list of terror-listed individuals since 2017.
Expected to take over soon
According to some analysts, Nasrallah has given his cousin tailored positions with the intention of Safieddine eventually taking over the organization.
As Israel has attacked a large number of Hezbollah's leadership in recent weeks, other potential claimants to power have been killed.
According to The New York Times, three sources within the terror-listed movement say that Safieddine's new position as Secretary-General of Hezbollah may be announced soon.