Apart from convictions for possession and supply in Italy, the most serious aspect of Maradona's involvement with drugs may be shown in a case going through the Rome courts in which he faces a charge of smuggling pounds 500,000-worth of cocaine into Fiumicino airport in 1990, the year of the last World Cup in Italy.
The case has being going on for several years and the related court documents and hearings have provided the best material to date concerning his alleged involvement with the Naples mafia and drug trafficking.
For seven roller-coaster years, Maradona played for Napoli following a transfer in 1984 from Barcelona for the then astonishing sum of pounds 7m. Naples, a city that had always felt humiliated by the richer, more powerful north, looked to the Argentine to reverse its fortunes. He soon delivered the goods. Naples won a European competition, the Uefa Cup, for the first time in 1989, and two league championships. He became the city's modern messiah.
The cocaine story first emerged after Maradona's well-publicised flight from Italy back to Argentina after he had failed a drugs test in 1991. The case centres on the testimony of a self-confessed murderer, Pietro Pugliese, a former security guard who worked for and claimed to be a friend of Maradona's in Naples.
As Maradona's career imploded in a blaze of publicity, Pugliese was dismissed as an unreliable witness - a publicity seeker who was attempting to blackmail the football star. But the situation changed dramatically last year when Pugliese turned on his old allies in the Camorra, the Neapolitan mafia, telling the authorities everything he knew about organised crime and confessing to five gangland murders.
Today, the Italian authorities take Pugliese very seriously indeed. His testimony has led to the arrests of 12 members of the Naples mafia and he is under 24-hour police protection.
These are the key facts drawn from his signed statement. In 1989, Pugliese was a guest at Maradona's wedding in Buenos Aires. He says that shortly afterwards the footballer asked him to organise transportation of a large consignment of cocaine from Argentina to Rome. In return he would be paid Lira75m (almost pounds 30,000).
During court hearings late last year, bank officials confirmed crucial evidence that the money - although less than Pugliese was owed - was indeed withdrawn and given in cash to him by a bank clerk. Maradona admits to the payment, but claims it was a loan.
Pugliese alleges he arranged for one of his girlfriends, Alessandra Bertone, to act as a courier. She was to collect a package from Maradona's manager, Guglielmo Coppola, in Buenos Aires and bring it to the footballer in Italy. Arrangements were made for her to travel with the Argentine team.
'Before the flight, Alessandra passed the Maradona Productions office, where they gave her the ticket and a heavy grey bag,' Pugliese said. 'They told her to keep it with her as hand luggage.'
On the basis of this evidence, Maria Cordova, the Italian judge leading the prosecution, said last December that there was now a reasonable case for the Italian authorities to ask for Maradona's extradition from Argentina.
'I think that if Maradona was to confront Pugliese, it would be more useful for the court of justice, and for himself - assuming he's innocent,' Cordova says.
The Pugliese case goes to the heart of Maradona's alleged involvement in organised crime and big league drug transportation. Ever since he arrived in Italy, rumours had begun to spread about Maradona's relationship with the Giuliano clan, one of the most feared crime families in Naples, with close links to football. Photographs seized from the home of a member of the family in 1986 by the Naples police included several of Maradona socialising with the mafia bosses. An investigation was launched into Maradona's links with the Camorra, but no action was taken.
It was not until 1991 that the Italian police managed to bring charges against Maradona, not for smuggling but for possession and supply of cocaine to prostitutes, for whom, despite his marriage, he had a voracious appetite.
Naples police intercepted a call to Camilla Cinquegrano, a well-known drug trafficker. They were listening into a major Camorra syndicate operating in Naples' Spanish quarter.
'We got to Maradona through his frequent conversations with big Neapolitan drug barons,' says Luigi Bobbio, the magistrate who investigated the case. 'He gravitated on the fringes of organised crime. Some of the people charged as a result of the very same investigation ended with heavy punishments - up to 15 years in jail.'
Bobbio says Maradona consistently denied charges of possession and supply during interrogation, but later, when presented with overwhelming evidence of violating the drug laws, he pleaded guilty.
But before Maradona could appear in court on possession and supply charges, he fled to Argentina following a positive drugs test. He was given a suspended sentence of 14 months and a pounds 2,000 fine in his absence.
Meanwhile, the police, investigating his rumoured links with organised crime and tax irregularities, continued to build a case against him on the much more serious charge of trafficking.
At first the Argentine authorities were anxious not to appear to be offering sanctuary to their favourite son. Three weeks after his return, Argentine crime reporters were tipped off by the police. They were about to bust the Golden Boy. The press had plenty of time to assemble before the police went in.
Having provided a reassuring spectacle, the Argentine authorities then sought to minimise Maradona's guilt. Despite being found with half a kilogram of cocaine, he was merely sentenced to rehabilitation under the care of his own doctor.
'He was caught, drugged up, with half a kilo of the highest purity cocaine,' says Enrique Sdrech, a journalist on Clarin, a leading Argentine daily. 'And in a few hours he recovered his liberty. A normal person would have got more than six years in jail.'
It seems incredible now that Maradona ever managed to get back into the game. But the man who almost single-handedly won the World Cup for his country in 1986 was still too important to Argentina in its bid for the 1994 championship. And he was still the biggest name in world football; he would bring glamour to a tournament where the stakes had never been higher.
Wheels began to turn. Fifa pulled strings to make sure that the US government would allow Maradona to enter the country.
'There are certain agreements with the World Cup. Now that doesn't guarantee anyone a visa, of course, but it does pretty much say we'll do what's within our effort to allow participants for the World Cup to come here,' said one State Department official. 'It's the same thing as when the Olympics were here.'
'Maradona, like any player in the game, should be protected,' Fifa's official spokesman, Guido Tognoni, said when asked before the World Cup about the footballer's drugs convictions and outstanding charges. 'Fifa wants to protect Maradona.'
A tetchy and defensive Luigi Grondona, president of the Argentine FA and a vice-president of Fifa, was more outspoken: 'Honestly, I always answer the same. It doesn't bother me at all. Diego began to play when I first became national president of this organisation. And, thanks to his conquests from then until today, I have become vice-president of Fifa.'
By the end of 1993, however, Maradona had been thrown out of Newell's Old Boys, the Argentine club to which he had returned. Although a corpulent and clearly troubled figure, he played for his country in the crucial World Cup qualifying tie against Australia. Despite an influential performance, it was clear that Maradona would have to lose a lot of weight if he was to become a decisive figure in the finals.
To the astonishment of many, he appeared in America almost two stone lighter, looking keener and fitter than for years. In retrospect, it seems unlikely this was achieved without medical assistance, and it now appears a desperate gamble that blew up in his face, with millions of football fans all over the world watching.
The Italian trafficking charges are still pending. It remains to be seen if Maradona will now be compelled to face the final hearing - and the verdict.