One of Italy's most notorious and ruthless Mafia bosses, Benedetto Santapaola, believed to have masterminded the murder of one of Italy's most famous anti-mafia prosecutors in 1992, has died in prison aged 87.

"Nitto" Santapaola was caught after years on the run in 1993, and spent more than 30 years behind bars for instigating a series of killings and other attacks.

Known as il cacciatore (the hunter), he rose to the top ranks of Sicily's Mafia in the city of Catania from the 1970s.

He was convicted of the 1984 murder of journalist Pippo Fava as well as a car bombing that killed judge Giovanni Falcone, in one of the most brutal attacks on the judiciary in Italy's history.

Falcone was blown up near Palermo in May 1992 in an an attack that also killed his wife and three police officers, in what became known as the Capaci massacre.

Weeks later anti-mafia judge Paolo Borsellino was also murdered in a car bombing in which his bodyguards were killed.

Nitto Santapaola was detained in a Sicilian farmhouse the following year.

In 2006, he was jailed for life for involvement in both attacks.

He was earlier convicted of involvement in the killing of fellow Catania mobster Alfio Ferlito and three police officers as Ferlito was being transferred to prison in 1982.

Santapaola was one of a number of Sicilian mobsters who were prosecuted for the two murders, and despite several trials, it was never clear who gave the order for the car bombings.

He was imprisoned amid tough security, under the so-called 41bis regime, an article of the Italian criminal code introduced after the two judges were killed.

The measures were originally meant to cut off mafia bosses from the outside world and other inmates, and to prevent them from ordering criminal acts from behind bars.

Santapaola died in the prison medicine department of the San Paolo hospital in Milan, after being transferred from the city's Opera prison due to declining health.