Equally, the officers who arrested him for shoplifting found nothing untoward about him. After he protested his innocence, they set about completing the paperwork and prepared to release him with no more than a formal caution.

So when a desk officer typed his name into a database as a matter of routine, the result made jaws drop. Spanovic, 43, from Carshalton, South London, was a convicted war criminal — sentenced to 20 years in jail in his absence — with an international warrant for his arrest.

He is said to have been part of a Serbian paramilitary gang that terrorised the village of Maja near Glina in the former Yugoslavia during the civil war.

Census figures show that, of the 274 people who lived there, only half a dozen were Serbs. The 40 gunmen drove into the village one morning in August 1991. As parents hurried to hide their children, the gang moved from house to house, stealing anything that took their fancy and destroying the rest. Anyone who protested was beaten. One man told the Croatian court that he was tortured and had the barrel of a gun shoved into his mouth.

The men told their victims that they would expel every Croat and bring Maja into their self-proclaimed breakaway Serb Republic of Krajina. They burnt down the village’s shop, social club and Roman Catholic church, and several homes. After the war, 19 men, including a relative of Spanovic, were indicted by the Croat Government for the raid. A Croatian court tried and convicted Spanovic in his absence. He has insisted that he was not responsible for any atrocities and was never in a terror squad.

He will appear at Westminster Magistrates’ Court today as Croatia seeks his extradition to Zagreb. He is thought to be the first Balkan war criminal to have been found in Britain.

Although the International Criminal Tribunal for the Former Yugoslavia at The Hague gets the headlines for its war crimes hearings, hundreds of other survivors from the Balkan wars are dealt with in their own countries.

If Spanovic is extradited he will have the right, under Croat law, to ask for a new trial.

Five months on from his arrest in June, neighbours in Carshalton still cannot believe that such a notorious figure was living among them.

The family lived quietly and, although they were polite to neighbours, they were reluctant to join in any social activities. Neighbours thought that Spanovic had arrived as an asylum-seeker in 1991 and were puzzled that he had no obvious source of income.

Sue Weatherburn, 39, a civil servant, said: “Ignorance is sometimes bliss. I’m not sure I would have wanted to know there was a war criminal here.”

One official in Zagreb said: “We are very grateful for his capture, though it is true we did not have Carshalton on our radar as a possible hideout. We had an international arrest warrant out for him, but we never expected him to be living a quiet life in London.”

There are thought to be fewer than 5,000 Croatians in Britain and investigators have never identified this country as a haven for Balkan fugitives.

ON THE RUN

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