AMSTERDAM – A hidden-camera video showing Jews being harassed on the street in a Moroccan neighborhood of Amsterdam has led Dutch authorities to consider combating hate crimes with “decoy Jews” — undercover police officers wearing yarmulkes.Enthusiasm for the unusual idea is a sign of the ongoing tension between the Muslim minority and the rest of the Dutch population over issues of immigration and crime. The idea of using “decoy Jews” to detect and arrest bigots has been embraced by both a prominent Moroccan politician and by Amsterdam’s acting mayor, who is Jewish. Law enforcement officials say the idea is feasible but would only be of limited practical use due to entrapment concerns. “It’s important that it not provoke any intent to commit a criminal act that wasn’t there in the first place,” Justice Minister Ernst Hirsch Ballin told parliament in a debate Thursday night on how to combat discrimination. Of course “it would be wrong to consider wearing a yarmulke itself a provocation,” he said. The idea of using police disguised as Jews was first mooted by member of parliament Ahmed Marcouch in a speech earlier this month. “We’ve done similar things with other kinds of crime,” he said. “I’ll act as a decoy Jew myself if necessary.” But the idea gathered momentum after the hidden-camera video aired on television last week. It was produced by the Joodse Omroep, a small Jewish broadcaster that gets an allotted amount of airtime each month on Dutch public TV stations. For the video, two youths and a Rabbi wearing yarmulkes went walking in a primarily Moroccan neighborhood in Amsterdam. The footage showed them quickly being subjected to a range of ill-treatment, from dirty looks to insults — and even, from one man, a Nazi salute. Decoy Jews are “not a solution to fighting anti-Semitism in general,” said Ronny Naftaniel, the head of the Center for Information and Documentation Israel, a pro-Jewish group that has lobbied for the idea. “But they could be used to fight a certain aspect: that Orthodox Jews are becoming unable to walk in public without being afraid of intimidation,” he said. Naftaniel said the main problem in policing hate speech crimes is that they are difficult to prove after the fact. With an undercover agent, offenders would be caught instantly, he said. The number of instances of reported anti-Semitism in Amsterdam rose in 2009 from the previous year, according to government data, from 17 to 41. Discrimination cases on the basis of skin color or country of origin rose from 232 to 336 in the same period, while anti-gay cases rose to 89 from 55. But those rises may reflect a public campaign encouraging people to report hate crimes. Hirsch Ballin told parliament Thursday police had seen no real increase in anti-Semitism. “The number of incidents rises and falls, and is connected to tensions in the Middle East,” he said. He promised to devote more resources to investigating hate crimes, as well as to more education in schools and a quicker legal process for discrimination-linked cases. His spokesman Wim van der Weegen said Friday that it would be up to individual prosecutors to decide whether or not they wanted to use decoy Jews. He said such sting operations need be approved in advance by a judge. Using surveillance cameras in certain areas is another option, Van der Weegen said. Amsterdam Mayor Lodewijk Asscher told a local television station this week he was open to the idea of using decoy Jews and other “unorthodox methods” to combat racism and homophobia. However, his spokeswoman, Tessel Schouten, said Friday the city doesn’t yet have any specific plans to do so.