Calvi's death by hanging in London in June 1982 is a source of enduring controversy and was ruled a murder after two coroners' inquests and an independent investigation.

Popular suspicion has linked his death to allegedly corrupt officials of the Vatican Bank, the Sicilian Mafia, and the Continental Freemasonry lodge Propaganda Due.

[citation needed] In 1978, the Bank of Italy produced a report on Banco Ambrosiano which found that several billion lire had been exported illegally, leading to criminal investigations.

[2][page needed] The controversy surrounding Calvi's dealings at Banco Ambrosiano echoed a scandal in 1974 when the Holy See lost an estimated US$30 million upon the collapse of the Franklin National Bank owned by financier Michele Sindona.

[3] Calvi wrote a letter of warning to Pope John Paul II on 5 June 1982, two weeks before the collapse of Banco Ambrosiano, stating that such an event would "provoke a catastrophe of unimaginable proportions in which the Church will suffer the gravest damage.

[8] Calvi went missing from his Rome apartment on 10 June 1982, having fled the country on a false passport under the name Gian Roberto Calvini, fleeing initially to Venice.

A postal clerk was crossing London's Blackfriars Bridge at 7:30 am on Friday, 18 June and noticed Calvi's body hanging from the scaffolding beneath.

[9] Calvi was a member of Licio Gelli's illegal masonic lodge Propaganda Due (P2), who referred to themselves as frati neri or "black friars."

The second inquest was held in July 1983, and the jury recorded an open verdict, indicating that the court had been unable to determine the exact cause of death.

When his body was found, the River Thames had receded with the tide, but the scaffolding could have been reached by a person standing in a boat at the time of the hanging.

Sergio Vaccari was a small-time drug dealer who had stayed in the same flat, and he was found dead in possession of masonic papers displaying member names of P2.

[21][22] According to Mannoia, the killer was Francesco Di Carlo, a mafioso living in London at the time, on the orders of Giuseppe Calò and Propaganda Due Worshipful Master Licio Gelli.

[20] In 1997, Italian prosecutors in Rome implicated Calò in Calvi's murder, along with Flavio Carboni, an allegedly mobbed up Sardinian businessman with wide-ranging interests.

[citation needed] In July 2003, Italian prosecutors concluded that the Sicilian Mafia acted in its own interests and to ensure that Calvi could not blackmail them.

[31] The defence suggested that there were plenty of people with a motive for Calvi's murder, including Vatican officials and Mafia figures who wanted to ensure his silence.

[32][33] Legal experts following the trial said that the prosecutors found it hard to present a convincing case due to the 25 years that had elapsed since Calvi's death.

[41] The 1983 PBS Frontline documentary "God's Banker" investigated Calvi's links with the Vatican and P2, and questioned whether his death was really a suicide.

[citation needed] In 1990, The Comic Strip Presents produced a spoof version of Calvi's story under the title Spaghetti Hoops, with Nigel Planer in the lead role, directed by Peter Richardson, and co-written by him and Pete Richens.

[43][citation needed] Variety magazine described the comedy film The Pope Must Die (1991) as "loosely based on the Roberto Calvi banking scandal".

[44][citation needed] In the 2009 film The Imaginarium of Doctor Parnassus, the character of Tony is found hanging alive under Blackfriars Bridge, which director Terry Gilliam described as "an homage to Roberto Calvi".