Israel jailed a suspected Jewish militant without trial on Tuesday, the first application of the controversial measure against a citizen in a government-ordered crackdown following the lethal torching of a Palestinian home.
The suspect, Mordechai Meyer, a resident of a Jewish settlement in the occupied West Bank, was arrested and placed under so-called "administrative detention" for six months, Israel's Defense Ministry said in a statement.
It accused him of "involvement in violent activity and recent terrorist attacks as part of a Jewish terror group".
Administrative detention, under which Israel holds hundreds of Palestinians and which civil liberties groups deplore as a blow to due process of the law, was among new measures Prime Minister Benjamin Netanyahu's security cabinet approved for Jews suspected in Friday's arson in the West Bank. The attack killed a Palestinian toddler and severely injured three relatives.
Detention without trial is required, Israel says, to prevent further violence in cases where there is insufficient evidence to prosecute, or where going to court would risk exposing the identity of secret informants.
Two other Israelis with ties to far-right Jewish groups, Meir Ettinger and Eviatar Salonim, were arrested this week. Police said the former was remanded in custody pending further investigation but was not placed under administrative detention. They did immediately detail Salonim's terms.
With years of sporadic Israeli hate crimes against Palestinians having turned fatal, and the security services complaining of a justice system that ties their hands in tackling suspects, Prime Minister Benjamin Netanyahu's government is at pains to show it has taken off the gloves.
Israeli commentators have questioned the resolve of security services which, when responding to Palestinian militant attacks, often round up suspects en masse as part of accelerated investigations.
According to Internal Security Minister Gilad Erdan, another new measure approved by the security cabinet on Sunday for Israeli suspects was the violent shaking of an uncooperative subject under interrogation, known in Hebrew as "tiltul".
Deemed a form of torture by liberties groups, tiltul's use was largely curbed by Israel's Supreme Court in a 1999 ruling.
Israel's top-rated Channel 2 television quoted Ettinger's lawyer as saying that his client had complained of being strapped to a chair by interrogators and shaken.
The lawyer could not be reached by Reuters for comment and police declined to respond, citing a gag order on the case.
Separately, Israeli police issued a rare public call on Tuesday for leads in the arson case. A police spokeswoman denied, however, that this signaled difficulties in the investigation.