An Israeli human rights activist says detainees were held with no access to food, water or restrooms and subjected to violent interrogations during the Gaza war.

Attorney Majd Bader of the Public Committee Against Torture in Israel (PCATI) testified in Geneva on Tuesday before a UN investigation team that is probing into the three-week Israeli onslaught against Gaza which started in December.

Bader told the committee that Palestinians seized during Operation Cast Lead were held in detention under "disgraceful" conditions and were subjected to violent interrogations by Israel Security Agency (ISA) -- commonly known as Shin bet.

Israeli forces held detainees in ditches where "50 to 70 people were squeezed into ditches two to three meters (6.5-10 feet) deep and some 50 meters (164 feet) wide," the Arab-Israeli lawyer later told reporters.

Being held blindfolded and handcuffed in a painful way are part of the Shin Bet interrogations which also included physical and verbal abuse, constant threats on the detainees and their families and sleep deprivation, he said.

According to Bader, the Israeli blockade on Gaza also prevented the detainees from meeting their lawyers and family members.

The lawyer criticized Israel's decision not to cooperate with the committee and said the boycott questioned Tel Aviv's confidence "in the moral and legal justification of its ways".

MRS/AA