Former President Ahmadinejad claims Iran's anti-Israel intel unit infiltrated by Mossad

The killing of Hezbollah head Hassan Nasrallah has sparked questions about how Israel could suddenly locate leading figures within the Lebanese movement after years of searching, with suspicions falling on Iran's intelligence.

Mahmoud Ahmadinejad - who served as Iran's president between 2005 and 2013 - believes his country's intelligence services could have been infiltrated by Israeli agents from the very top, with secret information passed on to the Israeli government.

This included an intelligence unit dedicated to rooting out Israeli spies in Iran, following attacks on nuclear scientists and facilities.

"Israel organized complex operations inside Iran. They could quickly obtain information," the former hardline president told CNN Turk.

"In Iran, they are still silent about this. The man who was in charge of the unit in Iran against Israel - was an Israeli agent."

He claimed that another 20 Israeli intelligence assets were in the force, passing on information about Iran's nuclear programme.

This came after rumours Israel might have penetrated Iranian or Syrian security to discover the location of top Hezbollah commanders.

While there is no proof to back Ahmadinejad's comments, and the president has a history of making outlandish comments and claims, Israel appears to have scored a massive intelligence bonanza by taking out Nasrallah and other Hezbollah leaders, though at the cost of massive civilian casualties.

Nasrallah was known to keep his movements strictly secret for decades and Israel failed to assassinate him during the 2006 war.

Other Hezbollah commanders killed in Israeli airstrikes include Ibrahim Aqil, Nabil Kouak, and Ahmad Wehbe, while senior Hamas figures such as Saleh Al-Arouri and Ismail Haniyeh have also been taken out in strikes, the latter in the relative safety of Tehran.

Nasrallah's killing was even more staggering, as it came just days after Israel managed to booby trap and detonate thousands of electronic devices used by Hezbollah and the public, despite presumably tighter security within the group

Israeli sources told Reuters that the killings were the result of 20 years of intelligence work focused on Hezbollah, with reports suggesting this information could have been gathered from the group's open operations in the Syrian war, where its fighters backed Assad regime forces on a number of frontlines.

The 7 October attacks indicated that Israel's focus on Hezbollah could have been to the detriment to intelligence gathering on Hamas.

Israel's military and intelligence have been widely slammed for failing to respond to repeated warnings on Hamas movements in the days and weeks leading up to the 7 October attacks.

Israel has also been unable to take out Hamas's military mastermind, Yahya Sinwar, and claims that Mohammed Deif, another key figure in the movement, was killed in an airstrike have also not been confirmed.