Anna Rosmus is used to such calls. That was her second that night. They have been going on now for more than a decade. Sometimes the callers simply warn of attacks against her; sometimes they talk of smashing up her house; the worst threaten to abduct her two daughters, Nadine, 11, and Salome, 8.
'I do not get spat at in the streets anymore, but I still get the death threats,' said Ms Rosmus. 'On average I receive about two a week. They do not frighten me as much as they used to. But I still have to be very careful.'
Although few would go so far as to say they would like to see Ms Rosmus dead, a lot of people in the picturesque German town of Passau would be more than pleased to see her gagged at least. For them, she is, indeed, The Nasty Girl of the 1990 film that shot both her and the town to international stardom, a constant thorn in the side of the Passau establishment.
Ever since 1981, when she entered a national essay competition innocently entitled 'My home town, 1933-39', she has left no stone unturned in her quest to reveal the extent to which the town connived in Nazi atrocities and was a heartland of rabid anti-Semitism both before and during the war.
In her latest book, Wintergreen - Suppressed Murder, due out at the end of this month, Ms Rosmus turns her attention to some of the many grisly crimes committed in the Passau area during the war, including the mass poisoning of children and executions of prisoners-of-war.
But she goes even further. In what she describes as a 'new type of war crime', the book also claims that a local gynaecologist, Dr Franz-Maria Clarenz, performed countless forced abortions on slave labourers from eastern Europe. If her words are to be believed, these really were a new category of atrocity: abortions carried out without the mother's consent, without anaesthetic and carried out on seven- and eight-month-old foetuses, ripped out of their mothers' wombs limb by limb.
If true, such deeds would rank alongside the most hideous crimes of all time. But doubt has been cast on her assertions. Earlier this month, the widow and children of Clarenz, who died in 1965, took Ms Rosmus to court - and won. Ruling that Ms Rosmus had failed to produce sufficient evidence to substantiate her claims, Judge Walter Zimmermann threatened her with a DM500,000 ( pounds 200,000) fine or six months imprisonment if she referred to Clarenz in connection with the atrocities again.
It was the first legal battle Ms Rosmus has lost. Insisting that her assertions were sourced to United States intelligence documents and Catholic Church archives, she said that the ruling was a classic case of the courts 'doing everything possible to protect the perpetrators of crimes rather than their victims'.
Despite the setback, she will carry on her investigations. But her endeavours have already cost her dear. She has been shunned by almost the entire Passau community and subjected to constant verbal abuse, 'Jewish whore' being just one of the variants. Her marriage cracked under the strain - for 'political reasons', she says - citing more explicitly her husband Manfred's disapproval of what she was doing and her insistence on inviting Jewish survivors of the Holocaust back to their home. Her studies of sociology, German literature and art had to be put on hold after she was inexplicably suspended from Passau university for four and a half years.
What made her do it? On the surface, she had had a model German upbringing. Her parents, both teachers, had brought her up as a good Catholic and she had shone in school. In 1980, a year before her controversial essay, she had won a national prize for another essay on 'Freedom in Europe' and had been celebrated by the town's leading dignitaries.
According to Ms Rosmus, it was a deep sense of the injustices of the past and a revulsion over the way in which the people of Passau tried to cover them up. 'Justice and personal freedom are the centre of my identity,' she says. 'I love these more than my broken marriage.'
In most of her early work Ms Rosmus, now 33 and still a student, focused on the eagerness with which Passau embraced the Nazi regime - and the speed with which it tried to forget it after 1945. 'The Catholic tradition of Passau is unbelievably full of hatred for the Jews, and has been for centuries,' she says, pointing out that that there were three concentration camps in or near the town and that it had unusually strong ties to Nazi leaders: Hitler was born just 20 miles away and lived in the town for a while, Adolf Eichmann and Heinrich Himmler both lived there. Even today, she adds, Passau is the setting for the annual rally of the far-right German People's Union (DVU), at which David Irving, the revisionist British historian, is a traditional guest of honour.
The fruits of her labour have been published in several award-winning books and articles. She has been hailed by leading Jewish figures worldwide and internationally acclaimed. But in Passau itself, where many leading politicians, priests and other community leaders have been exposed as Nazi sympathisers, she has, hardly surprisingly, won few friends.
'Anna Rosmus has put her fingers in wounds that never healed and are still not healed today,' said Klaus Hermann, a journalist with the Passauer Neue Presse newspaper which has been one of Ms Rosmus's fiercest critics. 'Of course people here wonder why she is dragging up the past like this and they resent the depiction of Passau as a particularly evil place.'
For many ordinary people in Passau, the ruling against her was greeted with joy. 'You could say there has been a great deal of schadenfreude over it,' said Mr Hermann. 'Many people here feel we have been unfairly singled out for opprobrium as a result of Ms Rosmus and now, at last, she herself has been told she has to stick to the facts. The truth is that Passau was neither particularly good nor bad during the war. Evil is committed all over the world, but no more so here than elsewhere.'
It is against precisely that sort of generalisation that Ms Rosmus, despite her legal setback, will continue to fight. She plans further books on the town's Jewish community and its concentration camps and will maintain her contacts with the few remaining survivors.
'I do not say that Passau was uniquely evil, but it is a good symbol of the Nazi time. We cannot erase the horrible memories, we cannot bring the dead back to life. But we can look and hope to learn from the past. That is the very least we can do.'