Hamas officials who were detained in the West Bank during an Israeli clampdown in June have accused Israel of maltreating them in custody.
Wasfi Kabha said he was questioned rigorously for 11 days
Wasfi Kabha and Hasan Khurayshah, who were released this week, both spoke of abuse at the hands of interrogators and poor living conditions in detention.
Israeli prison officials said Mr Kabha had been treated like other prisoners.
Israel still holds several ministers from the Hamas-led Palestinian government and members of parliament.
Mr Kabha, Minister for Prisoners' Affairs, told the Associated Press news agency that he had been released because there was no proof of Israeli allegations that he was a member of a terrorist organisation.
"I spent 11 days under heavy interrogation," he said by telephone from the West Bank town of Jenin.
"They would take me at 0500 in the morning, hands and legs cuffed, and place me in a chair without a back until 1700.
"The only rest I got was during the sirens when Hezbollah launched rockets at Israel. They would take me down into a cell underground and they would leave to take shelter somewhere in the jail."
His cell, he added, was "a small place with four dirty mattresses on the ground and with two very dirty and old blankets".
Hasan Khurayshah, a deputy speaker in the Palestinian parliament, earlier painted a similar picture of conditions he had allegedly experienced in custody along with Mr Kabha and Palestinian Finance Minister Omar Abdal Razeq.
"Everybody was treated in the same bad way," he told the pro-Hamas Palestinian Information Centre.
"They bound our legs and hands to a chair and put blindfolds so we could not see anything. There was very little water and food and they were unfit for human consumption. The jailers were cursing and insulting us."
Israel's Prisons Authority says all prisoners received clean clothes, sheets and toiletries.