Suspected Jewish terrorist Yaakov (Jack) Teitel told his interrogators he was an active member of anti-missionary group Yad L'achim for five years, Haaretz has learned.

The Bnei Brak-based ultra-Orthodox group has gained notoriety in recent years for its actions against Messianic Jews, whom it perceives as a "sect" seeking to convert Jews to Christianity. The organization also prides itself on "rescuing" Jewish women from relationships with Palestinians and Israeli Arabs.

Teitel, a resident of the settlement Shvut Rachel, was charged last November with murdering two Palestinians and attempting to murder three people, including Hebrew University Professor Zeev Sternhell and Ariel teenager Ami Ortiz. Ortiz, from a family of Messianic Jews, was gravely wounded by a bomb packaged inside a Purim gift in March 2008.

Teitel admitted to placing the bomb, and called the Ortiz family "missionaries trying to capture weak Jews."

Teitel admitted he was connected to the organization during an interrogation several weeks after his arrest. The interrogator, a Shin Bet officer with the Petah Tikva police, asked Teitel what he had been doing the night a bomb was placed outside Sternhell's home. Teitel said he had been pacing at home, unable to sleep, because of the cold weather.

When the interrogator asked Teitel how his wife would react when he would come home after spending the night out, Teitel said she didn't mind because she knew he was working with Yad L'achim, "rescuing" Jewish women from their Arab partners.

Teitel said he had worked with the organization for five years, and took part in five "rescue operations" a year. He said the operations were fast and effective, and always took place when the couples were not home. He refused to say who organized the operations.

A month and a half before Teitel's arrest, Haaretz spoke to Yad L'achim chairman Rabbi Shalom Dov Lifshitz, as part of a comprehensive feature on his group in the weekend supplement last October. In the interview, Lifshitz denied his organization was connected to the harassment of the Ortiz family, and when presented with a poster showing the family with other Messianic activists, the rabbi denied his activists were distributing it.

Two months after the explosion in Ariel, the injured teenager's father, David, approached several authorities in Israel and abroad. He said he felt the investigation had reached a stalemate, even though he had given police CCTV footage showing Teitel placing the bomb near his door.

Among others, he approached the Irish Christian Friends of Israel. The mission's staff then sought explanations from Israel's ambassador to Dublin, Nadav Cohen.

In response, the ambassador stated that the investigation was classified and that the officer in charge would tell him only that "Ariel has a community of about 20 Messianic Jews, and their leader [Ortiz] has been provoking Jews and Muslims, convincing them to convert ... the police is working to prevent this incident from recurring, but also told me that the Messianic Jews must alter their behavior to prevent extreme incidents in the future."

Caleb Meyers, legal adviser for the Jerusalem Institute of Justice, who represents several Messianic Jewish activists, said, "If Teitel's confession is correct, it's not particularly surprising. We have been warning about the daily incitement and violence by ultra-Orthodox organizations like Yad L'achim for years. They incite against minorities for no reason other than their religion."

"Yad L'achim is an entire barrel of bad apples," the lawyer said. "The authorities must treat them uncompromisingly, because it's just a matter of time before they grow more Teitel terrorists."

Yesterday, Lifshitz denied Teitel was connected to his organization.

"I have no idea who this is and we have nothing to do with him. I've read about him in the papers, and it sounds like he's making it all up with his feverish imagination. Maybe his claim about working with us was just an excuse to his wife for his absence at night."

Lifshitz also denied Teitel took part in five "rescue" operations a year.

"So he says, so what. I wish we had someone who could take part in five operations a year. Look, we have a lot of volunteers, hundreds of them, maybe he joined us under a false name," he said. "You can't know anything for sure these days. I guess I'll have to check the passports of every one of my men from now on."

The Yad L'achim chairman said he had not been approached by the police or the Shin Bet since Teitel's arrest.

"He's a wacko, he's nuts. I don't know the guy," he said.