IN Dublin, hysteria came to nothing.

All the old, dark prejudices and reawakened fears were turned to dust on an instant by a simple DNA test. Two distraught parents and their child had been subjected to an ordeal, albeit briefly, for no better reason than a mere suspicion.

As Roma, the couple were probably not surprised. Such has been the experience of their people time out of mind. For thousands in the middle of the last century, a harassed existence was ended brutally in the Nazi camps. Today, after one strange case far away, an Irish child can be snatched from her parents thanks only to tabloid headlines and a few racist assumptions based on blonde hair and blue eyes.

The seven-year-old girl taken from a house in Tallaght on Dublin's fringes simply because someone chose to doubt her parentage has been reunited with her family. A two-year-old Roma boy taken into care in Athlone has also been restored to his parents after 24 hours in the state's care. The Garda, Ireland's police, will now file their reports to explain, perhaps to excuse, bumbling cruelty. In the case of the girl, both a birth certificate and a passport were supplied. These were "doubted".

Roma are most often a dark-hued and dark-eyed people. This is one of those well-known facts that fails to be wholly true. In Greece, a child called Maria, right, one who does not fit the stereotype, became the centre of an international controversy because the science said, incontrovertibly, that Christos Salis and Eleftheria Dimopoulou were not her biological parents.

The Greek authorities charged Salis and Dimopoulou with abduction and remanded the pair in custody. The claim that they simply took in the child of a poverty-stricken mother was given no credence. Unicef, the United Nations children's agency, meanwhile asserted that perhaps 3000 youngsters in Greece were in the hands of child-trafficking rings.

Was this true of Maria? The answer, it transpired, was probably not. More DNA tests say she is the child of Bulgarian Roma, Sasha Ruseva and Atanas Rusev, a couple whose story seems to confirm the version given by Salis and Dimopoulou. Informal adoption, perhaps even an antique attitude towards kindness, might explain all.

That has not prevented suspicion falling on an entire, scattered community with no troubles to seek. Roma live, by choice and tradition, on the fringes of mainstream society.

Yet in country after country, the decision has been made to ensure that this is where they will remain. Laws and regulations in otherwise hospitable Ireland, for one example, give a message: Irish or not, these people are not welcome.

A group of just 5000 must meet the strict criteria of what is called the "habitual residence condition" to have any hope of receiving social security. Members of a community beset by literacy and language problems have a hard time acquiring a "personal public service" number for tax and employment purposes. These barriers have been raised in a country that has already been crippled, like Greece, by austerity. So how do Roma survive? The old, "obvious" answers come thick and fast. None is flattering.

In Ireland, things are not easy for this community. In eastern Europe, in countries such as Greece, Rumania and Serbia, where racism and hostility are often overt, things are much worse.

Little Maria was discovered, entirely by chance, when Greek police raided a Roma encampment. Why was this operation staged? The Greek authorities would call it routine. The police were certainly not looking for the little girl. Nevertheless, such raids have public approval.

The fact remains that Salis and Dimopoulou were not the furtive gypsies of legend. Like the family in Tallaght, like 90% of Europe's Roma, they were part of a settled community.

Nor was Maria kept locked away beyond the public gaze. She was living among people the Greek public did not want to see or hear save when police staged a raid. The child was not noticed because the Roma have been rendered invisible.

That fact alone has made accusations of child trafficking plausible. A people living on the margins, whether thanks to choice, prejudice or state action, are useful to criminals engaged in a vile trade. The response by bereft parents around the world to the discovery of Maria is proof enough that even now, in the 21st century, organised gangs steal children. With the Madeleine McCann case once again fresh in British minds, it is easy enough to draw conclusions.

That doesn't make Salis and Dimopoulou guilty. In Europe, where inquisitorial justice prevails, it is routine for those under suspicion to be charged and remanded before a proper judicial investigation of the truth can begin. Equally, there is little as yet to show that the couple are innocent: we don't know. What we do know is that ancient attitudes towards the Roma still prevail.

Would Irish police have behaved towards any other peoples in the manner suffered by those families in Tallaght and Athlone? Is crude racial profiling a fate reserved for Roma just because of "well-known facts"? Official denials come easily. Any number of ethnic groups are treated badly. If race, behaviour or belief mark you as alien, life can soon become hard. But in Europe, cradle of civilisation, the Roma people have been on the receiving end for centuries.

So what is it about people on the margins that mainstream society cannot tolerate? This summer a group of travellers camped for a while close to where I live in the Borders. To my knowledge, there was no local crime wave. Despite the usual gossip - dog-stealing is the new favourite allegation - public order was not put at risk. Yet when the vans and caravans were gone it was as though no-one had ever occupied a derelict field.

The clearing of Dale Farm in Essex two years ago this month gave one insight into attitudes towards "travellers". They owned that land. Some of them had been there for years, on a patch adjacent to an authorised site, with solid houses. The claim that the land was green belt was disputable, to say the least. Yet because of convoluted arguments over planning permission Basildon Council provoked a huge police action to clear families from their homes.

Why would people placed in such a situation want to be integrated? Why would they embrace those who treat them with contempt? The facts of the Maria case might turn out to be grim.

But since when did evidence of a single crime justify discrimination towards an entire people? We know the answer. If Salis and Dimopoulou turn out to be guilty, things will become hellish for the Roma across Europe.

It is a fragile, insecure society that cannot tolerate anyone who fails to live always and exactly in accordance with what is deemed normal. That, nevertheless, is the only offer made to the Roma. Be like us, become like us - or else. Yet look at the names of the accused. Those are Greeks, not aliens. Much good it will do them.