The Israeli army on Monday ordered a Palestinian journalist to be detained without trial for six months, less than a year after freeing him following a prolonged hunger strike.

In May, Mohammed al-Qiq, 34, was released from a six-month prison term without trial following a 94-day hunger strike.

He was rearrested last month for his alleged activities in the militant Islamist group Hamas aimed against Israel as well as undermining the Ramallah-based Palestinian Authority, the Shin Bet domestic security service said at the time.

On Monday, his wife Fayha Shalash said he was on hunger strike again. The prison service confirmed this, without saying when the fast had begun.

A controversial Israeli administrative detention law allows the state to hold suspects without trial for periods of six months, renewable indefinitely.

The army said on Monday he was given the new six-month term without a court hearing, based on intelligence that Qiq "continues to be an operative for the Hamas terror group who incites dangerously to harm Israeli citizens".

A military spokeswoman told AFP that administrative detention was "a last resort" measure employed as they had no other way of "neutralising the danger" Qiq posed.

He has denied the Israeli allegations about militant activity, saying he works for the Saudi television channel Al-Majd.

Qiq's case was widely covered last year, and the United Nations expressed concern about his condition during his previous time in prison.

He was jailed for a month in 2003 and for 13 months in 2004 for Hamas-related activities. 

In 2008, Qiq was sentenced to 16 months on charges linked to his activities on the student council at the West Bank's Birzeit University.