Anni-Frid was persecuted as a child of the 'master race', reports Kate Connolly. Now people like her want justice

When Abba sang 'Knowing Me, Knowing You', there was one member of the cult Swedish pop group for whom it had a special meaning.

The brunette Anni-Frid Lyngstad is one of thousands of people who grew up in Scandinavia shunned, persecuted and parentless. It is alleged that some were even used as guinea pigs in drugs trials.

Known as the Tyskerbarnas or German children, they were the offspring of Norwegian mothers and German soldier fathers, the result of a Nazi plan to 'enrich' the Aryan gene pool.

Now the group of up to 12,000, of whom many are now in their sixties, plans to fight for compensation in the European Court of Human Rights.

Anni-Frid Lyngstad's story is typical of the suffering of thousands. After her birth in November 1945 - the result of a liaison between her mother, Synni, and a German sergeant, Alfred Haase - the infant's mother and grandmother were branded as traitors and ostracised in their village in northern Norway. They were forced to emigrate to Sweden, where Anni-Frid's mother died of kidney failure before her daughter was two.

The child found her father by chance three decades later. They met for an emotional reunion in her Swedish villa, instigated by Benny Anderson, an Abba founder and Anni-Frid's then husband.

Afterwards, the singer said of the meeting and her father: 'It's difficult... it would have been different if I'd been a teenager or a child. I can't really connect to him and love him the way I would have if he'd been around when I grew up.'

The depression she subsequently suffered was attributed by friends to the delayed encounter with her long-lost father, a retired pastry cook.

The somewhat morose Anni-Frid, who withdrew for years in Greta Garbo style, is nevertheless viewed as something of a role model by her fellow Tyskerbarnas still living in Norway.

'She's achieved amazing things in Sweden, something she would never have been able to do had she stayed in Norway, where she would have been branded a freak,' says Tor Brandacher, 63, spokesman for the organisation representing the children. Founded in 1999, the group, Krigsbarnforbundet Lebensborn, or Source of Life, takes its name from the scheme run by Heinrich Himmler, the leader of Hitler's feared SS, to create a master race.

It has been pursuing its claims for compensation for abuse and discrimination through the domestic courts. The case, involving 122 people, argues that the wartime Norwegian government - led by the notorious Quisling - was complicit in the Nazi scheme to breed with blonde, blue-eyed Norse women. The government asserts that if crimes were committed, they happened too long ago to be dealt with now.

The case is now going to the country's Supreme Court, but the victims and their families are preparing to take it to the European Court of Human Rights. 'Having been rejected by Norway so far, we have little choice but to take our case further afield,' says Brandacher.

'We see Norway as a rundown gas station in comparison to the gleaming motorway service station that is the ECHR in Strasbourg,' says a hopeful Brandacher, himself the son of an Austrian elite Gebirgsjäger soldier. He says the Norwegian government is likely to face huge embarrassment once the case receives full international attention.

Most of the Lebensborn children who stayed in Norway are social misfits. Few have received proper education or been employed. 'It's typical that they've suffered from depression and low self-esteem,' says their lawyer, Randi Hagen Spydevold.

'Most have had problems forming relationships or being able to relate to the real world, which is hardly surprising when you've spent your formative years being called a German idiot, a no-good bastard who doesn't deserve to be alive.'

Had Germany won the war, they would almost certainly have been heroes. But Germany lost, and soon afterwards the Norwegian mothers lost their status, and their children were classified as 'rats' by government officials.

The postwar hatred towards the offspring of German soldiers was so great that government psychologists commissioned to report on the children and their mothers concluded that women who had fraternised with Germans were 'of limited talent and asocial psychopaths, some of them seriously backward'.

The verdict 'father was a German' was indictment enough to send children to mental hospitals, where many were tortured and raped. They were deemed to be dangerous because of their 'Nazi genes' and capable of forming a fascist fifth column.

Quisling's government was desperate to be rid of the problem and attempted to send the Tyskerbarnas as far afield as Brazil and Australia. Sweden was praised for taking several hundred and thus relieving Norway of an embarrassing 'problem'. Around 250 were sent 'back' to Germany.

Many thousands of their mothers - labelled 'German whores' - were sent to Norwegian 'concentration camps', where they were virtually slave labourers.

Of those children who ended up scattered around 128 Norwegian children's homes, many were released from their virtual prisons as bewildered adults only in the early Sixties into a world of which they had little or no experience.

When her case comes before the supreme court, Spydevold has as one of her witnesses a highly-experienced judge who will testify that a high percentage of the criminals he has seen have been the result of the Lebensborn experiment. 'He will testify that through the Norwegian government's neglect of them, many turned to crime,' Spydevold told The Observer .

But in many ways the most shocking aspect of the whole story is what happened to the children in the homes. In a separate case, Spydevold is attempting to bring the Norwegian government to task over documented evidence of drugs trials carried out on both children and mothers.

Witnesses and documents say experiments with LSD, mescaline and other substances were initiated by the Norwegian military, Oslo University and the CIA.

For Harriet von Nickel, born in March 1942, the road to justice is long but worthwhile. 'As a two-year-old living with foster parents, I was chained up with the dog in the yard,' she says in German Child, her best-selling autobiography.

'As a six-year-old I was thrown in the river by a man from my village, who said he wanted to see if "the witch will drown or float",' she writes.

At the age of nine or 10, she says, drunken villagers from Bursr, near Trondheim, branded her forehead with a swastika made of bent nails, and threatened to rape her. 'A woman saved me, and I rubbed sandpaper on my skin to get rid of the swastika.'