A French- lawyer will spend at least three more months detained without charge under a controversial detention practice, court documents show.
Israeli authorities overnight on Sunday extended the detention of Salah Hamouri, 37, under what is known as , according to the documents.
The practice allows suspects to be detained without any charges for renewable periods of up to six months.
An Israeli military court sentenced Hamouri to administrative detention in March. It accused him of being a member of the Popular Front for the Liberation of Palestine (PFLP), and said he "endangers security in the region".
Hamouri, who holds French citizenship, denies being a member of the PFLP.
The military court documents, sent to his lawyers and seen by AFP, say that his administrative detention has been extended to September 5.
Hamouri has been arrested and jailed by Israeli authorities on several occasions, including in 2005.
Following that arrest, he was tried and convicted by an Israeli court on charges of plotting to assassinate Ovadia Yossef, a prominent Israeli rabbi and spiritual leader of the ultra-Orthodox Shas political party.
Hamouri was released in December 2011 as part of a swap of more than 1,000 Palestinian prisoners for Gilad Shalit, a soldier held captive in Gaza for more than five years.
He has always maintained his innocence.
In April, Hamouri filed a complaint in France against surveillance firm NSO Group for having "illegally infiltrated" his mobile phone with Pegasus spyware.
He is one of several Palestinian activists whose phones were hacked using the Pegasus malware, according to a report in November by human rights groups.