The staggering allegation - flatly denied by Mr Andreotti yesterday - was disclosed less than 24 hours after Italians had voted by an overwhelming 82.7 per cent to throw out their old scandal-ridden political system and start anew.
The claim was made by Baldassare Di Maggio, Riina's former driver, whose evidence led to the capture of the feared boss in January after 24 years in hiding. The Palermo magistrates investigating suspicions against Mr Andreotti sent the testimony to the Senate's immunity commission to back their request for authorisation to proceed against him on suspicion of associating with the Mafia.
'I am absolutely certain that I recognised Giulio Andreotti because I saw him many times on television,' Di Maggio allegedly told the magistrates. 'I interpreted the kiss that Andreotti and Salvatore Riina exchanged as a sign of respect.' Respect is a Mafia term for honour, given by mafiosi to leading members of the organisation or someone who is important to them.
Di Maggio said Riina had told him to dress smartly, and they went to the Palermo flat of Ignazio Salvo, a leading Mafia figure who was later murdered. 'When we arrived the people present who I recognised without a shadow of doubt as Giulio Andreotti and Salvo Lima (Mr Andreotti's chief Sicilian political associate) got up and greeted us. In particular, I shook the hands of the two parliamentarians and kissed Ignazio Salvo . . . Riina on the other hand greeted all three with a kiss (Andreotti, Lima and Salvo)'.
Di Maggio, who gave a detailed description of the flat, said the meeting lasted between three and three-and-a- half hours.
The latest batch of material sent to the commission also contains alleged evidence that Mr Andreotti met other mafiosi. It includes what are purported to be photographs of him with the relatives of a Mafia member at a religious event in Rome. Mr Andreotti was earlier accused of ordering the Mafia to carry out two political murders.
The allegations were a reminder that the past still needs clearing up, as Italians exulted over the outcome of the referendum for a new electoral system that, it is hoped, will make corruption and abuses much harder.
'Now we can rebuild,' rejoiced Mario Segni, leader of the reform campaign. 'The new Italy is born,' announced the Corriere della Sera. 'An avalanche of 'yeses' has buried the old regime,' declared La Repubblica, adding that 'today is the first day of the new Republic'.
The 'new Italy' will take its first tentative steps tonight, after the Prime Minister, Giuliano Amato, tells parliament his government is at an end. In the ensuing debate, which will continue tomorrow, the political parties will declare what they want to happen next and how.
Later in the week, once Mr Amato has formally resigned, President Oscar Luigi Scalfaro will pick someone to form a government to push through the electoral reforms that the country has demanded.
But the post-referendum euphoria is being drowned out by the sound of politicians squabbling. The future Second Republic clearly has a difficult and controversial path ahead. The political parties and the groups that campaigned for reform disagree wildly over what kind of government Italy should have next. Some favour an 'institutional' government, led by the speaker of one of the houses of parliament and with ministers divorced from any party allegiance.
Others want a government of the 'yes' vote - meaning the groups that fought for change - with Mr Segni as prime minister. However, Mr Segni has insisted he is not interested in
Yet others advocate a government of technicians, while a second government led by Mr Amato - but with a wider base - is not ruled out. In fact, it has been practice for presidents to ask outgoing prime ministers to have another try, and President Scalfaro may choose this route, too.