JERUSALEM — Leaders of the right wing are accusing the Israeli government of using the Shin Bet to stir up public sentiment against their efforts.

The charges came amid reports that one of the suspects who had been detained in connection with the assassination of Prime Minister Yitzhak Rabin had been an informant for the Shin Bet, Israel's domestic intelligence agency.

The reports about Avishai Raviv, a leader of the militant Eyal movement with which Rabin's confessed assassin was connected, touched off a furor throughout the country.

The controversy erupted as the Cabinet decided to crack down on extremist Jewish groups and launch efforts to prevent supporters of the groups abroad from entering the country.

Raviv was also reportedly involved in distributing posters of Rabin in a Nazi uniform at a right-wing protest in early October. That was the sort of inflammatory gesture some have said created the atmosphere leading to the Nov. 4 assassination.

Rabbi Benny Alon, a member of the right-wing Moledet Party from the West Bank settlement of Beit El, said last week that he had recordings proving Raviv's ties to the Shin Bet.

Raviv, who was released from custody this week and placed under house arrest, denied the reports, as did the Shin Bet.

The 27-year-old Holon native said the reports linking him to the Shin Bet were "ridiculous." He said he had been involved in right-wing extremist groups since his teens.

Despite the denials, later disclosures in the media cited security sources as saying that Raviv had, in fact, worked in some capacity for the Shin Bet.

Some reports said Raviv had passed confessed assassin Yigal Amir's name to security officials, but had identified him only as a right-wing extremist and gave no information of any plot to assassinate the prime minister.

In the wake of the reports, right-wing politicians and activists charged that the Shin Bet had used Raviv in an effort to discredit what they said were legitimate protests against the government's peace policies with the Palestinians.

Former Knesset member and Kiryat Arba settler Elyakim Ha'etzni said Raviv's handlers in the Shin Bet should be put on trial.

Zvi Katzover, chairman of the Kiryat Arba settlers council, told a news conference this week that he knew of at least two more Shin Bet plants in the settler community, who were "stirring up" Jewish youths to attack Arab property.

Some observers suggested that it would not be surprising for the Shin Bet to plant someone among right-wing extremists; they described it as a traditional method of intelligence gathering.

They also said a number of questions remain over the exact role Raviv allegedly played, his reliability as a source of information and the effectiveness with which the security service processed the information it received from him.

Along with the allegations about Raviv, the police investigation of the Rabin assassination has also prompted growing criticism.

Amir has claimed that he alone carried out the killing. But the police, without offering any specific evidence, have been pursuing the possibility that Amir was part of a conspiracy.

Besides Amir, eight people including one woman have been arrested in connection with the alleged conspiracy. The roundup has prompted a relative of one of those arrested to claim that it is a "hysterical government that is taking these measures."

The government is "depriving people of their civil liberties," said Pnina Peli, grandmother of Margolit Har-Shefi, the only woman detained so far.

Peli, who described her granddaughter in a telephone interview as a "quiet, popular student," said she had "no connection with militarist groups." Har-Shefi is a student at Bar-Ilan University, where Amir also studied.

Peli said Har-Shefi was not allowed to see a lawyer for days after she was detained and was being subject to brutal treatment in the prison where she is being held.

Amid all the allegations and controversy, the government agreed at Sunday's Cabinet session to appoint a special task force to look into the legal ramifications of its proposed crackdown on right-wing extremist groups.

The task force will be comprised of representatives from the attorney general's office, the police, the Israel Defense Force general staff and the Shin Bet.

Meanwhile, Education Minister Amnon Rubinstein has elaborated on a plan to prevent supporters of extremist groups from entering Israel.

"People who support illegal organizations or their members cannot come to Israel, not as citizens, not as tourists, not as returning residents and not as immigrants," he said.

The Law of Return, which grants citizenship to any Jew who wishes to immigrate, includes a clause that allows the Interior Ministry to refuse entry to any individual deemed to pose a threat to public safety.

Last week, Interior Minister Ehud Barak barred a Kach activist from New York from entering Israel. Kach has long been outlawed in Israel.

In keeping with this policy, Uri Gordon, head of the Jewish Agency's Immigration and Absorption Department, has instructed all immigration emissaries, or shlichim, in North America to tell Israel about right-wing extremists wishing to make aliyah (immigrate).

Rubinstein rejected complaints from the main opposition Likud Party that the crackdown on right-wing extremists amounted to a witch hunt.

"There is no shred of evidence to that effect," Rubinstein told Israel Radio. "It is our duty to fight Jewish terrorism."

The state commission of inquiry held its first week of secret testimony, hearing from security officials who were charged with the protection of Rabin and other Israeli leaders.

The three-member panel, headed by former Supreme Court Chief Justice Meir Shamgar, is expected to conclude its work within two months, according to local media reports.

The commission is investigating the security lapses that enabled Amir to get within point-blank shooting range of Rabin at the conclusion of a massive peace rally in Tel Aviv.

On Monday, meanwhile, a Tel Aviv judge extended the period of detention for Amir, who expressed no regret for killing Rabin.

"It was not only my finger that pulled the trigger, but the entire nation which for 2,000 years dreamed about this country and spilled its blood for it," Amir told the court.

Amir, who charged that Rabin was not a legitimate leader, was cut short by Judge Dan Arbel, who said the courtroom was not the place for political speeches.

Under Israeli law, Amir last week re-enacted the assassination in the Tel Aviv city hall parking lot where Rabin was killed Nov. 4. Filmed by police, he pulled out a toy pistol and fired three shots at a police officer playing Rabin.

Amir has refused legal representation, saying he is the best one to represent himself. Some Jews in Brooklyn are reportedly raising money for his defense.