Italian Mafia boss Matteo Messina Denaro, who was one of the country's most wanted men until his capture earlier this year, has died.
The 61-year-old was thought to be a boss of the notorious Cosa Nostra Mafia and spent 30 years on the run before he was detained in January.
He was being treated for cancer at the time of his arrest and was moved from prison to hospital last month.
Denaro was thought to have been responsible for numerous murders.
He was tried and sentenced to life in jail in absentia in 2002 for crimes including involvement in the 1992 killing of anti-Mafia prosecutors Giovanni Falcone and Paolo Borsellino and once boasted he could "fill a cemetery" with his victims.
He also oversaw racketeering, illegal waste dumping, money-laundering and drug-trafficking for the Cosa Nostra organised crime syndicate.
Although he had been a fugitive since 1993, Messina Denaro was thought to have still been issuing orders to his subordinates from various secret locations.
According to local media, he fell into an irreversible coma on Friday at a hospital in the central Italian city of L'Aquila, after requesting that he be given no aggressive medical treatment.
He had undergone surgery in recent months for issues to do with his cancer, but had reportedly not recovered following the latest operation.
L'Aquila Mayor Pierluigi Biondi confirmed Denaro's death, writing on X (formerly Twitter) that it was "the epilogue of an existence lived without remorse or regret, a painful chapter in recent history that we cannot erase."
Alongside his crimes, Denaro was thought to be Cosa Nostra's last "secret-keeper". Many informers and prosecutors believe he held all the information and the names of those involved in several of the most high-profile crimes by the Mafia.
More than 100 members of the armed forces were involved in his arrest in January, which happened at a private clinic in Sicily's capital, Palermo, where he was receiving chemotherapy.
For years, he had been a symbol of the state's inability to reach the upper echelons of the organised crime syndicates.
Italian investigators often came close to catching Denaro by monitoring those closest to him. This resulted in the arrest of his sister, Patrizia, and several of his associates in 2013.
Police also seized valuable businesses linked to him, leaving him increasingly isolated.
However, few photos of him existed and police had to rely on digital composites to reconstruct his appearance in the decades after he went on the run. A recording of his voice was not released until 2021.
In September 2021, a Formula 1 fan from Liverpool was arrested at gunpoint in a restaurant in the Netherlands after being mistaken for Denaro.