Ayatollah Mohammed Yazdi
Ayatollah Mohammed YazdiReuters

A hardline cleric has been elected to head the committee which will select Iran's new Supreme Ruler, in the event that current leader Ayatollah Ali Khamenei dies, Reuters reports.

Ayatollah Mohammad Yazdi's selection to head the Assembly of Experts comes not long after reports circulated that Khamenei had died of prostate cancer - rumors Iran was quick to squash with a video, purportedly from later on that day, of the Supreme Leader meeting environmental activists.

But the 75-year-old leader, who wields ultimate power in the Islamic Republic, is in relatively poor health; just last year he underwent surgery for prostate cancer.

Yazdi's election will cause further concerns in both Israel and among western states over the direction Tehran is taking. It comes just weeks before a March 31 deadline for a deal over the Iranian regime's nuclear program, and at a time when Tehran seems more eager than ever to expand its control over the region by funding Shia Islamis militias in Lebanon, Iraq and Syria.

It will also go further toward proving assertions by many that the election of supposed "moderate" Hassan Rouhani as president in 2013 was simply a ruse to bolster Iran's standing in negotiations with the west, given that the Supreme Leader has ultimate authority over him.

The radical cleric beat former president Ayatollah Ali Akbar Hashemi Rafsanjani to the top spot by 47 votes to 24, according to the semi-official Fars news agency - an unexpected outcome for many observers, who saw Rafsanjani as a clear favorite.

"This was unexpected," said Mashallah Shamsolvaezin, an Iranian journalist and political analyst based in Tehran. "I was genuinely surprised that Yazdi won."

The Assembly of Experts has only had to choose a new Supreme Leader once since the Islamic Revolution: in 1989, following the death of Khamenei's predecessor, Ayatollah Ruhollah Khomeini. It also has the power to dismiss the Supreme Leader, though that has never happened.