An Israeli military court has extended the detention of Abd al-Aziz Dweik, the Palestinian parliament speaker, until next Tuesday.
On Thursday, Dweik, 57, who was hospitalised with chest pain after his arrest earlier this month, shouted to television cameras at the court hearing complaining that his arrest was unjust.
"I am the elected representative of the people," he said.
"This is unjust treatment by an occupation which lacks legitimacy. We do have the right and the legitimacy, but these [Israelis] are unjust and usurpers [of land] who do not observe human dignity or human rights.
"My rightful place is among the people."
Dweik, whose hands and feet were cuffed, said he has been held in solitary confinement. Dweik, a Hamas member, was elected in January elections that gave the Islamist resistance group an overwhelming majority.
He opposes the extension of his detention until he receives a medical examination. He also said he did not recognise the legitimacy of the court.
His defence team says his health is deteriorating. He was taken to hospital earlier in his detention amid claims he had been beaten.
The defence has also stated that Israeli soldiers had forced Dweik to take a medicine that caused him to lose concentration and balance.
Asked by Aljazeera regarding his health, Dweik, an academic, said: "My health condition is bad, but my determination is stronger than Israel's injustice.
"Justice will triumph, the oppression will end, while the Palestinian people will remain heroes," he added.
Dweik was seized by Israeli forces on August 7 from his home in Ram Allah in the West Bank. Israel is holding tens of Hamas politicians.