Russian officials have confirmed that the leader of the Russian mercenary group Wagner died in a plane crash in western Russia on 23 August.

Yevgeny Prigozhin staged a failed mutiny against Russia's military leaders in June, and had gone to Belarus afterwards with hundreds of Wagner fighters.

The group's future is now very uncertain.

Prigozhin said he founded Wagner in 2014.

Although mercenary forces are illegal in Russia, Wagner registered as a "private military company" in 2022.

Prigozhin was a wealthy businessman and convicted criminal, known as "Putin's chef" because he provided catering for the Kremlin.

Wagner's first field commander was Dmitry Utkin, a former officer in Russia's special forces. He said the group was named after his radio call sign.

Most Wagner mercenaries initially came from Russia's elite regiments and special forces, and the group was thought to number about 5,000.

However, in 2022, Prigozhin recruited prisoners from Russian jails to fight for Wagner in Ukraine, in exchange for pardons. In June, he said there were 25,000 Wagner fighters.

The group has also been operating in Syria, Mali, the Central African Republic, Sudan and Libya.

Russian aviation officials said Yevgeny Prigozhin and nine other passengers died when a private plane flying between Moscow and St Petersburg crashed in the Tver region, north of Moscow on 23 August.

Dmitry Utkin was also on board.

The Investigative Committee said the identities of all 10 victims had been established, after genetic analysis of the bodies, and that it was conducting a criminal investigation into the crash.

UK defence sources have told the BBC that Russia's FSB intelligence agency is most likely to have been responsible.

Wagner troops were heavily involved in the battle for Bakhmut, a city in eastern Ukraine, which they captured for Russia in May 2023.

During the fighting, Prigozhin repeatedly criticised Russia's army chief, Valery Gerasimov, and defence minister, Sergei Shoigu, for under-supplying Wagner's troops, many of whom were killed or injured.

In June 2023, some 5,000 Wagner fighters staged a mutiny. They occupied the southern Russian city of Rostov-on-Don and marched on Moscow, with the stated aim of ousting Gerasimov and Shoigu.

Prigozhin halted the advance after making a deal with Russian President Putin, which was negotiated by the Belarusian leader Alexander Lukashenko.

Putin said Wagner's fighters could either join the regular Russian army or go to Belarus with Prigozhin.

In July, a US military spokesman said Wagner troops were no longer thought to be "taking part in hostilities" in Ukraine.

The Polish government has been reported as saying it believes there are between 3,500 and 5,000 Wagner mercenaries in Belarus.

They are thought to be based at military camps in the south of the country, at Tsel and Brestsky.

The Belarusian defence ministry says they are training the country's territorial forces.

In a speech to Wagner mercenaries in Belarus in July, Prigozhin said the group would "set off on a new path - to Africa."

An estimated 1,000 Wagner fighters have been in Mali, in western Africa, since December 2021.

They were hired to combat armed Islamist groups, replacing the UN and French peacekeeping forces which had previously operated there.

Wagner forces have clashed several times with a group linked to al-Qaeda called Jama'at Nusrat al-Islam wal-Muslimin.

In a recent video recording, apparently filmed in Africa, Prigozhin said: "We're making life a nightmare for ISIS [Islamic State] and al-Qaeda and other bandits."

There are an estimated 1,000 Wagner fighters in the Central African Republic (CAR).

The UK government says they operate behind a front organisation called the Officers Union for International Security.

That group's leader has said it is training soldiers in CAR to fight rebel forces, and has been helping to protect supply lines to cities.

A Wagner company called Midas allegedly makes money from gold mining in the country.

Video evidence suggests Wagner has been in Sudan since 2017, providing military training and helping to crack down on protestors.

In 2017, Sudan's government awarded gold mining contracts to Prigozhin's company, M-Invest. In July 2020, the US imposed sanctions against the company and its subsidiary Meroe Gold.

In Libya, Wagner troops are supporting the forces of General Khalifa Haftar.

Wagner's mercenaries have also been in Syria since 2015, supporting pro-government forces and guarding oilfields.

The US Treasury says Wagner companies have made profits from oil and gas deals there.

Ukrainian prosecutors say three Wagner mercenaries killed and tortured civilians near Kyiv in April 2022, alongside regular Russian troops.

German intelligence says Wagner troops may also have massacred civilians in Bucha in March 2022.

In 2020, the US military accused Wagner mercenaries of planting landmines and similar devices in and around the Libyan capital, Tripoli.

In July 2023, the UK sanctioned Wagner's businesses in Africa, accusing it of "executions and torture in Mali and the Central African Republic and threats to peace and security in Sudan".