The parents of Mordechai Mayer - the 18-year-old Jewish activist placed under administrative detention Tuesday - have told of their utter shock at their son's sudden incarceration without charge.

Meir is one of three right-wing activists arrested in recent days, following a firebombing last week at the Arab village of Duma in Samaria which killed a young child.

However, there is no indication that any of those arrested were involved in that crime, and their lawyers have all accused authorities of conducting a witch hunt to placate international pressure to crack down on "Jewish terrorism." 

But while the other two youths - Meir Ettinger and Evyatar Slonim - are being held under "regular" police arrest, Mayer is being held under a six-month "administrative detention order," a legal relic from the British occupation which allows authorities to hold terror suspects without charge.

At a press conference Wednesday, his parents denied he had been involved in any violent crime, and said the police were "scapegoating" him.

"Our children love Israel - that's what we raised our children to be like and they're definitely following in that way," his mother said, rejecting claims her son subscribed to a militant, anti-Zionist ideology. "They love people, and frankly, we're in shock."

"Our son was detained in the house for about a week and then last night there was a knock at the door and they showed us a paper, and on the paper it said they were going to take him to some sort of a jail for six months," his father recounted.

"No word on why they're doing this, no word on that he was suspected of... some crime - no word on anything just... taking him to jail with no accusation, with nothing."

"We left America, which is a democracy; we came to Israel which is also a democracy, and we found that they can take away an 18-year-old child, who hasn't as far as we know done anything or been charged with anything - take him to jail for a half year and never charge him with anything!

"They needed to arrest somebody... he was a scapegoat."

On Tuesday, the Honenu legal aid organization responded to the administrative arrest, calling it "a loss of control by the Defense Ministry."

"The fact that just two days ago the same youth was given an administrative house arrest order, and already it's been decided to 'upgrade' the order to an administrative arrest, shows the populist management of the authorities," wrote Honenu.