Mojtaba, 56, Ali Khamenei's second oldest son, has strong links to the Iranian Revolutionary Guard Corps (IRGC), and was chosen by Iran's Assembly of Experts 'under pressure from the Revolutionary Guards', according to Iranian opposition outlet Iran International.

Mojtaba is not a high-ranking cleric, has never held office and does not have an official role in the regime. 

But he served in the Iranian armed forces during the Iran-Iraq war and is believed to wield considerable influence behind the scenes. He has been touted as a possible successor to his father for years.

However, he was not included in a list of three senior clerics Ali Khamenei reportedly identified last year. 

And his father is said to have indicated opposition to his candidacy because it would resemble the hereditary rule enacted by the US-backed Shah monarchy before it was overthrown in the Iranian Revolution in 1979.

Father-to-son succession is also viewed negatively in the Shiite Muslim clerical establishment in Iran.   

But much of Iran's top brass has been decimated in the latest conflict and Mojtaba has close ties with the powerful IRGC and the Basij volunteer paramilitary force.

Despite being sanctioned by the US in 2019, Mojtaba is said to oversee an investment empire of over £100million, with access to luxury properties in north London and bank accounts in the UK, Switzerland, UAE and Liechtenstein.

Mojtaba is said to own 11 properties on The Bishops Avenue - an exclusive street in Hampstead, north London, also known as 'Billionaires' Row'. 

The Ayatollah's second son owns the properties through a network of shell companies, one of which is registered in the tax haven of the Isle of Man. 

Under Iran's Islamic guardianship system, the Supreme Leader must be a senior leader with significant political authority. 

While Mojtaba has not held senior political roles, he studied under religious conservatives in Islamic seminaries in the Shiite holy city Qom. 

Born in 1969 in the holy city of Mashhad, he grew up as his father was helping to lead the opposition to the Shah.

His wife Zahra Adel and his mother, Mansoureh Khojasteh Bagherzadeh, are among the dead from Saturday's strikes.

In recent years, a favorite to succeed the 86-year-old Supreme Leader had been the hardline President Ebrahim Raisi, but he was killed in a helicopter crash in May 2024.