The family of the most prominent Palestinian prisoner, Marwan Barghouti, says that he has again been subjected to physical violence behind bars in Israel. Arab Barghouti told the BBC he was 'shocked and appalled' to hear from his father's Israeli lawyer that he had been assaulted three times by Israeli prison guards in the past month. The Israeli Prison Service (IPS) said that 'the allegations made are false and baseless'. Marwan Barghouti was convicted by an Israeli court of planning deadly attacks against Israeli civilians and is currently serving five life sentences plus 40 years. He was arrested exactly 24 years ago, at the height of the Palestinians' second intifada, or uprising. He had set up the Tanzim, an armed wing of the Fatah political faction. Opinion polls indicate that despite his imprisonment, Barghouti is the most popular Palestinian leader. He remains a member of the Fatah Central Committee. Many Palestinians view the 66-year-old as their equivalent of South Africa's Nelson Mandela and point to his ability to unite different political factions and his past rapport with Israeli leaders. Arab Barghouti argued that his father's prominence had led to him being singled out for attacks and abuse. 'He's someone who represents hope for unity, for democratic renewal, for a better future for the Palestinian people,' he said. 'He's a target because he gives hope to the Palestinian people.' The Israeli lawyer, Ben Marmarelli, visited Barghouti in prison on Sunday and reported severe incidents of violence against him by prison guards. Reports indicate an increase in claims of abuse of Palestinian prisoners since the escalation of violence in the region. Rights groups have called attention to a 'de facto state policy of organised and widespread torture and ill treatment' of Palestinian detainees. In September, Israel's Supreme Court ordered improved conditions for Palestinian inmates due to insufficient food supply. Currently, 9,560 Palestinians are held in Israeli jails as security prisoners.