The torture and murder of a young Jewish man in Paris triggered outrage among Jewish leaders yesterday as the Government sought to prevent the affair from inflaming emotions in the Muslim-dominated housing estates of France.

Dominique de Villepin, the Prime Minister, and his ministers promised that justice would be done after the parents of Ilan Halimi, 23, who was held captive for three weeks on an immigrant estate, accused the police of playing down the anti-Semitic motives of his kidnappers.

Voicing the anger felt among the Jewish population, Radio Shalom, a station in Paris, said that M Halimi had “been made to pay for the (Danish) cartoons of Muhammad and Abu Ghraib”, the prison where US forces tortured Iraqi captives.

M Halimi, who worked in a telephone shop, died shortly after being found ten days ago naked and bound on a suburban roadside. Police denied any racial aspect in the kidnapping and ransom demands, but on Monday investigators added racial hatred to the kidnapping and murder charges that six men and a woman in police custody are facing.

The kidnappers are alleged to have referred to M Halimi’s Jewish background in their telephone and e-mail demands to the family for ransom, and one of the young torturers was reported by accomplices to have stubbed out a cigarette on M Halimi’s forehead while voicing his hatred for Jews.

The seven are alleged to be part of a loose gang of young estate-dwellers who had already made six unsuccessful kidnap attempts against residents of Paris. Nicolas Sarkozy, the Interior Minister, told Parliament yesterday that four out of the six were Jewish.

Two officers flew yesterday to Ivory Coast in pursuit of Yussef Fofana, 25, the alleged ring-leader who calls himself “Brain of the Barbarians”, who flew out of Paris after M Halimi was found. The gang had used women to entrap their victims by chatting them up and arranging dates with them.

One intended victim, a 50-year-old Jewish man identified as Michael, told how he had been lured to an estate and knocked out with a blow to the head from a pistol butt. He had been saved after residents called police, but spent a week in hospital. According to unconfirmed reports in the Jewish community of Paris, at least one family has recently paid a ransom for the release of a kidnapped child.

As M Sarkozy visited M Halimi’s parents yesterday, the Simon Wiesenthal Centre sent him a message saying: “These acts are a test for Europe. Jihadi violence, hatred and anti-Semitism must be prevented from taking root in French soil.”

Ruth Halimi said that her son might still be alive had the police not evaded the nature of his kidnapping as they were negotiating over ransom.

“We told the police that there had been at least three other attempted abductions of young Jews, but they persisted in considering the motives purely criminal because they are afraid of reviving a clash with the Muslims,” she said.

Police said that the gang appeared to have been driven by greed and the crude racial stereotypes that prevailed on the estates. Feuj, slang for Jew, is a common insult in the ghetto-like estates. The group had been influenced by television, particularly the Abu Ghraib torture pictures, officers said.

In Parliament, M Sarkozy played down the kidnapping as a religious or political act. “These thugs acted first of all out of sordid criminal motives in a search for money, but they were convinced that ‘Jews have money’,” he said.

M de Villepin was reported yesterday to have reprimanded Pascal Clément, the Justice Minister, for quoting one of the accused kidnappers as saying M Halimi had been abducted “because he was Jewish, and Jews are rich”. His discretion reflects official fear of stirring the anger that drove thousands of young men from Muslim-dominated estates to a frenzy of fire-bombing last autumn.

France has Europe’s biggest Muslim and biggest Jewish populations. The actions of the gang contrast with a big drop in reported anti-Semitic acts in France over the past year.