Raisi was heading to the city of Tabriz, in the north-west of Iran, after returning from a dam opening ceremony on the Azerbaijan border.

Iran’s Mehr news agency also confirmed the deaths, reporting that “all passengers of the helicopter carrying the Iranian president and foreign minister were martyred”.

The incident happened near Jolfa, a city on the border with Azerbaijan, about 375 miles (600km) northwest of the Iranian capital, Tehran.

Concerns had been growing for the 63-year-old ultraconservative Raisi after contact was lost with the aircraft on Sunday as it navigated fog-covered mountains in north-west Iran.

In the early hours of Monday, a Turkish drone located a “source of heat suspected to be the wreckage of helicopter carrying Iranian President Raisi”, according to Turkey’s state-run news agency Anadolu.

More than 70 rescue teams using search dogs and drones were sent to the site, the Red Crescent said.

The chief of staff of Iran’s army ordered all the resources of the army and the elite Revolutionary Guards to be deployed.

Raisi had been in Azerbaijan early on Sunday to inaugurate a dam with the country’s president, Ilham Aliyev. The dam is the third that the two nations have built on the Aras River.

Iran owns several helicopters, but international sanctions make it difficult to obtain parts for them and most of its military air fleet pre-dates the 1979 Islamic Revolution.

Raisi is a hardliner who formerly led the country’s judiciary. He was viewed as a protege of Iran’s supreme leader, Ayatollah Ali Khamenei.

He won Iran’s 2021 presidential election, for which the turnout was the lowest in the Islamic Republic’s history.

Raisi was under sanctions by the United States in part over his involvement in the mass execution of thousands of political prisoners in 1988 at the end of the bloody Iran-Iraq war.

Under Raisi, Iran has been enriching uranium at nearly weapons-grade levels and hampered international inspections.

Iran has supplied arms to Russia in its war on Ukraine and launched a drone and missile attack on Israel. It continues to arm proxy groups in the Middle East, such as Yemen’s Houthi rebels and Lebanon’s Hezbollah.

Iran’s Vice President, Mohammad Mokhber, is likely to be appointed as the interim president by Iran’s Supreme Leader, who ultimately has the last say in all matters of state.

An election for a new president is due to take place in the next 50 days.

Mokhber (68) was elected as the first vice president after the 2021 elections that saw Raisi come to power.

He will be a part of a three-person council to organise a new presidential election in the next 50 days.

Mokhber visited Moscow in October 2023 when Iran agreed to supply surface-to-surface missiles and more drones to Russia’s military.

Sky News’ international affairs editor, Dominic Waghorn, described Raisi as the “‘butcher of Tehran”, saying he was one of Iran’s hardest of hardliners, a fanatical and absolute believer in the Iranian revolution and its mission. He said:

A man who launched the first direct attack on Israel in his country’s history and a hardliner on whose watch hundreds of Iranians have been killed in the brutal repression of recent women-led protests, Mr Raisi had a huge amount of blood on his hands.

His fearsome reputation went back to the 1980s – a period that earned him the dubious soubriquet the Butcher of Tehran.

He sat on the so-called Death Panel of four Islamic judges who sentenced thousands of Iranian prisoners of conscience to their deaths during the purge of 1988.

Mr Raisi was personally involved in two of the darkest periods of Iranian repression. And he was seen as one of the favourite contenders to replace the elderly and ailing Supreme Leader Ali Khamenei.

More: Pindula News