At first sight the case against Erich Priebke seems a straightforward, if emotionally fraught affair: a piece of historical justice finally tidied up after more than 50 years of neglect. Surely, one supposes, the only harm that this 83-year-old man, with his dapper grey suits and Tyrolean hats, can still do at this stage is to stir up unpleasant memories. It is only a matter of time, one feels, before the Rome military court does its duty and lays the past finally to rest.
If only it were that simple. The longer the Priebke trial goes on - it has been in progress for just over a month - the more sensational and terrifyingly relevant it becomes. Old documents thought lost and old SS officers long thought to be dead have suddenly popped up to challenge the official version of history. The list of organisations suspected of protecting Priebke in South America for so many years now includes the Vatican, the CIA and Mossad, the Israeli counter-espionage service.
According to several witnesses, the secret network known as Odessa, which smuggled scores of Nazis out of Europe into exile in the 1940s and 1950s, is still operating, helping Hitler's old underlings in Latin America to build up commercial links with multinational companies in Europe and the US. Plenty of old Nazis continue to live as well as Priebke used to, not because they have managed to disguise their true identity - indeed, many are happy to use their real names - but because they enjoy international protection at the highest level.
This sounds like the stuff of fantasy spy thrillers, but the passions it has aroused are all too real. Take the case of Karl Hass, a fellow SS officer of Priebke's during the war, who promised to be the prosecution's star witness after he made some explosive allegations in advance interviews with the Rome newspaper Il Messaggero. Nobody realised Hass was still alive until two weeks ago, when prosecutors tracked him down at his home in Switzerland and persuaded him to testify.
But last Thursday night, a few hours before he was due to take the stand, something or someone spooked Hass so badly that he decided to run for it. Not daring even to walk out of the front door of his hotel, he tried instead to climb out of a second-floor window. Perhaps inevitably for an 84-year-old, and an asthmatic at that, he slipped, breaking his pelvis as he crashed down on a row of flowerpots.
Later, as he lay immobilised in Rome's main military hospital, Hass failed to give a coherent account of what he had done, describing it only as "a moment of idiocy". Yesterday, when he was finally heard by prosecutors in a special session around his sickbed, he went ahead with his testimony but changed his story completely, in effect backing up Priebke's line of defence and admitting for the first time that he had taken part in the massacre himself.
What kind of a man is Erich Priebke that he can still cause such histrionics half a century after the events in question? What ghouls remain to be exorcised from those dark wartime days, when all of Rome lived in the shadow of the Gestapo's headquarters on Via Tasso? For many years, Priebke's reputation made him out to be the typical Nazi bureaucrat, a man whose cruelty stemmed less from the torture and killing that went on under his nose than from the obsessive pleasure he took in codifying and cataloguing it all in bland, euphemistic language.
Gradually, however, evidence has accumulated that Priebke was rather more than a passive participant in the horrors of Nazism. According to declassified documents compiled at the time by the US secret services, Priebke volunteered for the Gestapo as early as 1936 and was soon employed to draw up lists of Jews, gypsies and other undesirables destined for deportation to the death camps.
Several Resistance fighters who suffered in the cellars of the Gestapo building in Rome have testified that Priebke himself took turns as a torturer, punching his victims in the ribs with a knuckle-duster and telling them: "I'm sorry, but you have to talk. You're going to be shot anyway, but you can avoid a lot of suffering that you won't be able to resist."
The massacre at the Ardeatine Caves showed Priebke in his most sinister light. On 23 March, 1944, during celebrations to mark the 25th anniversary of the rise of Fascism in Italy, a detachment of SS officers was blown up by a Resistance bomb left in a dustbin in Via Rasella in the centre of Rome. Priebke's boss, Herbert Kappler, received word from Berlin that 10 people were to be rounded up and shot in retaliation for each of the 33 soldiers killed. It was Priebke who compiled the list of the victims, picking Jews, Resistance fighters and their families (the youngest just 15), and common criminals culled from the city's Regina Coeli jail; it was Priebke who also ticked off their names as they were led in groups of five or six into a dank corner at the back of the caves and shot through the back of the neck. The cave was later blown up in a half-successful attempt to cover up the evidence. Some of the victims have never been identified; quite who did the shooting has never been fully established either.
Somewhere along the line, five extra names were added to the list, bringing the total number of people killed in the massacre to 335. Priebke insists this was mere oversight; those who knew him at the time, however, suspected him of deliberately inflating the total out of sheer vindictiveness.
It was on the basis of these extra names that Priebke, Kappler and four others were ordered to stand trial before an Italian military tribunal in 1948. At the time, the court broadly accepted the excuse that participants in the massacre had been obeying orders and that they risked being executed themselves if they did not comply. Kappler, who took responsibility for the five extra deaths, was sentenced to life imprisonment, while the four others were acquitted. Priebke himself never went to trial because he had escaped from a prisoner-of-war camp in Rimini and disappeared.
Where had he gone? According to Nazi-hunters as well as several old Nazis, Priebke was spirited out of Italy via the "ratline", an escape route organised by a pro-Nazi German bishop called Alois Hudal with the blessing of Pope Pius XII. The Vatican has always denied the existence of the ratline, but when Priebke eventually resurfaced in San Carlo de Bariloche in Patagonia, one of his next-door neighbours turned out to be a close associate of Bishop Hudal's, a former German army lieutenant called Reinhard Kops.
So many old Nazis ended up in Bariloche that it turned into a veritable German colony. Many residents said that the mountains and the plentiful German restaurants made them feel as though they had never left Bavaria. Priebke fitted right into this world, running first a hotel and then a delicatessen specialising in cold cuts of German sausage. In due course he became chairman of the local German-Argentine Cultural Association and governor of a newly built German-language school. He never felt the slightest concern about the past catching up with him; he kept his old name and old passport and was regularly listed in the local telephone directory.
His peace might never have been disturbed but for an ABC television crew who, with the help of the Simon Wiesenthal Center, tracked him down and interviewed him in March 1994. Priebke denied killing anybody at the Ardeatine Caves, but the ABC team also unearthed a confession he had made in 1946 in which he admitted shooting two of the victims personally. Suddenly the whole case burst open again; within two months Priebke was under arrest, and last November he was at last flown back to Italy for trial.
Only now has the full weirdness of the affair begun to come to light. According to several experts consulted during the trial, Priebke and countless other Nazis in Latin America enjoyed high-level protection from international security services. The Chilean writer Luis Sepulveda believes it is a conspiracy that even includes Mossad. Mossad succeeded in finding Adolf Eichmann, one of the architects of the Final Solution tried and executed in Jerusalem in 1961, and yet never managed to find Josef Mengele, the notorious "angel of death" who conducted vile experiments on the inmates at Auschwitz. "Mossad knew Mengele was in Paraguay looking out for certain interests," Sepulveda claimed on a visit to Rome a few days ago.
It seems Karl Hass was about to reveal similar information before his abrupt change of heart. In his newspaper interviews, Hass said he had himself been protected and had thus been able to remain incognito in Italy, where he lived until recently, while the world assumed he had died. He also offered tantalising new leads on the whereabouts of the gold the Nazis stole from the coffers of central banks around Europe. Half, he said, was still buried beneath a fortress near Bolzano in the South Tyrol, while the other half had disappeared from its hiding place under Monte Soratte just north of Rome.
Hass also intended to shed new light on the age-old conundrum: whether SS members were really obliged to carry out the massacre on pain of death, or if they participated willingly. Before his botched night-time flit, Hass said the notion that the massacre had been "compulsory" was merely a ruse that the SS had invented to avoid prosecution after the war. This coincided with testimony from other witnesses, including - from beyond the grave - Herbert Kappler himself.
A few days ago, as if by magic, an old television interview with Kappler resurfaced in which the Gestapo chief admitted telling his subordinates to lie about their complicity in the massacre and plead that they were forced to obey orders.
It is hard to know what to believe any more, whether witnesses to this trial are acting in good faith or being manipulated by occult forces still active half a century after the defeat of Nazism. Evidence has a habit of jumping out of nowhere, then vanishing back into the ether.
To guess what might happen to Priebke, one should first look at the fate of his old boss, Herbert Kappler. Here was a man who looked set to spend the rest of his days behind bars. But then in 1977, his wife managed to spirit him out of a Rome military hospital in a suitcase and he spent the remaining few months of his life in freedom. A gesture of humanity by the Italians towards a sick old man? Or a sinister international plot? The Priebke trial is bringing all the old rumours bubbling back to the surface, and raising more questions than it can possibly hope to answer.