Unearthed: the true story of Roberto Calvi's death

For years, police believed it was suicide. But a new inquiry is finally shedding light on the dark plot that lay behind the demise of 'God's Banker'. An exclusive report by Jason Bennetto

It has all the ingredients for a Hollywood film script - a mysterious killing, a cast of Mafia hoods, a Masonic conspiracy, a multi-million-pound fraud, the involvement of the Vatican, and the whiff of a political scandal. But the full story of how the Italian banker Roberto Calvi ended up hanging dead underneath a London bridge is only just emerging, following a fresh investigation by a team of detectives from the City of London police and the Italian authorities. The inquiry is due to be completed in the next few weeks, but The Independent has obtained details of the findings, which for the first time reveal exactly how Calvi was killed and why. It also points towards the possible killers.

It was at about 9pm on a June evening in 1982 that Roberto Calvi left his Chelsea flat to enjoy a meal of pasta and beans. After his late supper, the 62-year-old walked the short distance to the north bank of the river Thames and boarded a boat. The banker thought he was being treated to a twilight pleasure cruise days before he was due to leave London to start a new life with his family in the United States.

It was while he was standing on the boat that his killer came up behind him and placed a rope around his neck. His assassin garrotted him, pulling the orange cord with such force that he lifted his victim into the air. As Calvi struggled, his feet dragged along the deck leaving deep scrape marks on the heels of his shoes. Shortly after midnight on 18 June, the lifeless body was taken to Blackfriars Bridge, where the murder weapon had been tied into a lover's knot and placed around his neck. His killers placed two lumps of concrete in the financier's underpants and two into the trousers of his grey suit, along with $15,000 in cash. The rope was then tied to some scaffolding on the bridge and the body was allowed to slip into the water. At the time it was high tide, so by the early hours of the morning the water had retreated and the body was found hanging from a steel pole.

The death caused a sensation when it was discovered that the victim was chairman of Banco Ambrosiano, Italy's biggest private bank, and the man known as "God's banker" because of his close ties to the Vatican. At the time, the bank was under investigation in Italy and three months later collapsed with debts of £800m.

Over the years the death of Calvi has become one of the most intriguing unsolved crime cases and financial scandals of modern times. For years, the banker was thought to have committed suicide, but the police now believe Calvi was the victim of a classic Mob hit and his body was strung up on the scaffolding as a warning to others who might dare to the cross the Mafiosi. The man responsible for the fresh inquiry is Detective Superintendent Trevor Smith, an experienced detective who moved from the Met to the City of London force last May. His first job was to re-investigate the Calvi case.

Calvi was a hunted man in his final days. As head of Banco Ambrosiano he was in charge of the finance house used by the Mafia to launder its crime money and was fully aware of the illegal activities going on at the bank. Indeed, he is believed to have taken advantage of his position to siphon-off about £50m belonging to the Mafia. He also had knowledge of the corrupt connections with a number of leading Italian politicians - one very senior member is still in power - and the financial secrets of the Vatican, whose bank, the Institute for Religious Works,had a shareholding in Ambrosiano.

Calvi was also in trouble with the law. He had been convicted of illegally taking foreign currency out of Italy and had been given a four-year prison sentence, which he was appealing against. The Mafia, Smith believes, was terrified that Calvi would turn informer in return for escaping a stretch in jail. To prevent this the Italian crime syndicate had a plan. The Mob persuaded Calvi to flee Italy after telling him he had lost his appeal; in fact, no decision had been made. The frightened banker was aided by Flavio Carboni, a wealthy Sardinian businessman and confidant of Calvi. Armed with a fake Venezuelan passport, Calvi and Carboni went to Britain via Switzerland and Austria. The Mafia put Calvi up at a furnished flat at Chelsea Cloisters on Sloane Avenue, London. The city was supposed to be a stopping off point before Calvi travelled to America - possibly to Venezuela or Panama - where he was supposed to be joined by his family.

The Mafia choose London as scene of his demise for several reasons, the police believe. In the early 1980s, the organisation had a powerful grip on the capital's cocaine market and there were a number of low-ranking lieutenants eager to prove their worth with their bosses in Italy. It was also a far more discreet place for an execution. As Det Supt Smith explains: "To have killed him in Italy would have caused a fire storm. It would have been highly difficult for the Mafia to distance themselves from his death. It gave them some breathing space."

The murder was carefully orchestrated to look like suicide and at first the authorities were fooled. An inquest held five weeks after Calvi died ruled he had committed suicide, but his widow Clara and the couple's son Carlo, a financial administrator now living in Canada, complained successfully that the proceedings had been rushed through and that the police did not do their job properly in the first few crucial days. A second inquest was held the following year, but it added to the confusion by returning an open verdict.

It would take events in Rome nearly 20 years later to persuade the City police to look again at the Calvi case. In 2002, following a new postmortem on Calvi's exhumed remains, forensic scientists appointed by Italian judges concluded he was strangled before being hung from the scaffolding. Then, that December, a Mafia supergrass called Antonio Giuffre told police Calvi had been murdered because Mob bosses were angry at the way he had mishandled their money. He said that Giuseppe "Pippo" Calo, a high-ranking Mafia paymaster currently serving a long prison term, was the man who organised the crime.

It was at this stage that the City of London police inquiry was set up. At its peak, there have been 40 officers working on the case along with specialists using forensic science techniques not available in 1982. The team staged a reconstruction using the original scaffold poles and examined the victim's possession and autopsy results. Smith says a re-examination of the evidence has convinced him that the suicide theory "can't hold water". "A man in his sixties, who was overweight and not in good health, would have had to go down a ladder about 20-30ft, climb onto a scaffolding and shin along a pole, tie a rope to it and around his neck, then lower himself down while carrying four lumps of concrete, two in his underpants and two in his trousers," he says. A scientist even put bricks in his underpants and re-enacted the "suicide". The unfortunate expert suffered chaffing to his thighs from the weights; Calvi's body had no such marks. Similarly, the scaffolding poles left iron filings on the shoes and hands of the forensic specialist, but nothing was found on the dead man. Markings and damage to the vertebra in Calvi's neck suggested there were two points of strangulation. There were also clues found on the victim's footwear. "I think he was standing when he was strangled," says Smith. "There are indentations on the shoe heels that are freshly worn; if you are garrotted you would trash about and drag your feet on the floor. The scientific and medical evidence says 'not suicide'. So it was either an act of God or someone who wants to pretend he is God with the power of life and death. I'm satisfied it is the latter."

The police investigation also concluded that Calvi died while on a boat. Officers were able to trace several vessels from photographs of Thames river boats owned by various suspects, but as yet have failed to identify the exact spot the murder took place. Smith continues: "I think he was strangled on the boat and then put on the bridge. He was probably garrotted with the same rope from behind. I think what happened next was that they tied the rope around the scaffolding, the tide was high, and the boat just pulled away leaving the body behind."

To add to the intrigue, Calvi was hanged from Blackfriars Bridge. The significance of the location was that Calvi belonged to the powerful Masonic lodge P2, known for years as Italy's shadow government. Member of P2 referred to themselves as frati neri - "black friars". But Det Supt Smith is unconvinced by the conspiracy theory. "I'm not sold on the Masons link. I'm sold on the idea of the Mafia making it look like a suicide, a very public one, but those in the know would know that the real message was - this is what happens to people who cross us. It was a message to other people - look what happens if you try and rip us off."

Smith believes that at least one other murder in London is linked to the affair. Two months after Calvi was killed, Sergio Vaccari, an Italian drug dealer, was stabbed more than 15 times in his face, neck and chest in his flat in west London. Vaccari, who is now thought to have been responsible for hiring the boat on which Calvi was killed, is believed to have been silenced after threatening to turn informer unless some drug debts were written off.

The City of London police inquiry has thrown up another potentially significant development. In December in west London, officers arrested Odette Morris, 42, a woman who provided an alibi at Calvi's first inquest for Flavio Carboni, the man who escorted the banker across to Britain. Morris was held on suspicion of conspiring to pervert the course of justice and perjury, and questioned about allegations that she provided a false alibi to Carboni. She was later bailed. The potential significance is that Carboni is one of the four people accused in Italy of plotting to murder Calvi; if his alibi is discredited, it will be a serious blow to his defence. Carboni, a wealthy and influential business figure, has vehemently denied any involvement in the murder. The other three charged with conspiracy to murder are Calo, a top figure in the Sicilian Mafia who is currently serving a life sentence for a 1984 train bombing that killed 16 passengers; Ernesto Diotavelli, a leading figure in Rome's underworld; and Manuela Kleinszig, an Austrian citizen and, at the time, a girlfriend of Carboni's.

There are three people being investigated for the strangulation. One is Francesco Di Carlo, known as Frankie the Strangler, who was in London at the time of Calvi's death. Di Carlo, who was jailed for 25 years for smuggling heroin and cannabis into Britain and is in Italy currently serving the sentence, has denied killing Calvi. Silvano Vittor, a small-time coffee smuggler who, with Carboni, was instrumental in arranging Calvi's flight to London with a false passport, is also being investigated, along with another man who cannot be named for legal reasons.

Calvi's son, Carlo, 50, and his 82-year-old mother have spent a small fortune on hiring private investigators in their attempt to bring the killers to justice. Calvi believes the authorities are getting ever closer to uncovering the truth. He says: "I'm not looking to have anyone sent to the electric chair or anything like that. I'm more interested in the legal process. I believe this is a story that has many consequences and lessons for Italy - and it is one that appears to be drawing finally to an end."