A human rights group says the Egyptian government bears responsibility for the death of former Egyptian President Mohamed Morsi, amid pressing international demands for a fair and transparent investigation into the circumstances surrounding his final hours.According to authorities, the first democratically elected president in Egypt's modern history died on Monday after collapsing in a court in Cairo while on trial on espionage charges. The Egyptian public prosecutor said a medical report showed no apparent recent injuries on Morsi's body.The 67-year-old, who had been behind bars for nearly six years after his overthrow in a military coup in 2013, had a long history of health issues, including suffering from diabetes as well as liver and kidney disease.Rights groups and international observers had long decried the medical neglect Morsi was suffering during his "harsh" imprisonment, including years of solitary confinement."The government of Egypt today bears responsibility for his death, given their failure to provide him with adequate medical care or basic prisoner rights," Human Rights Watch (HRW) said in a statement to Al Jazeera."He's been in prison and treated worse than the already terrible conditions for Egypt's prisoners," Sarah Leah Whitson, executive director of the HRW's Middle East and North Africa division, told Al Jazeera, decrying Morsi's "terrible but entirely predictable" death."The Egyptian government has known very clearly about his declining medical state. He had lost a great deal of weight, he had fainted in court a number of times and was being kept in almost around-the-clock solitary confinement."HRW's statement echoed a report released in March 2018 by a panel of British members of parliament and lawyers, which warned that the lack of medical treatment could result in Morsi's "premature death"."Our conclusions are stark," Crispin Blunt, chairman of the Independent Detention Review Panel, said at the time."The denial of basic medical treatment to which he is entitled could lead to his premature death," he added."The whole overseeing chain of command up to the current president would have responsibility for this."The members of the panel were denied access by Egyptian authorities to visit Morsi, and relied on testimonies, witness statements, NGO reports and independently submitted evidence.They said that Morsi was being kept in solitary confinement for 23 hours a day, which under the UN guidelines, would classify as torture."He has been held under conditions that we found on the balance of probability was actually so bad - in terms of how degrading they were and how tough they were for him - that they could amount to torture," Blunt told Al Jazeera on Monday."Torture is a crime of universal jurisdiction. And we found that the responsibility for that would sit all the way up the Egyptian chain of command," he added. "So, if they had looked after him since our report, then it would be in Egypt's own interest to establish [an independent inquiry]." Also on Monday, Amnesty International urged the Egyptian authorities "to conduct an impartial, thorough and transparent investigation into the circumstances of Morsi's death, including his solitary confinement and isolation from the outside world"It also called for a probe into the medical care Morsi was receiving, and for anyone found responsible for mistreatment to be held accountable.'Unlawful isolation'The calls cames two years after the HRW reported that Egyptian authorities had unlawfully isolated Morsi, preventing him from contacting or receiving visits from his family and lawyers since the military coup in 2013.On June 4, 2017, Egyptian authorities allowed Morsi to receive visits from his family and lawyer for only the second time in nearly four years, according to the HRW.These conditions undermined Morsi's right "to mount a legal challenge to his detention and a defence against the many prosecutions filed against him" and may have contributed to a decline in his health, HRW noted."Morsi's treatment is a window into the appalling conditions suffered by thousands of political detainees in Egypt," Joe Stork, HRW's deputy director of Middle East and North Africa, said at the time.According to the report, during the first week of June in 2017, Morsi fainted twice and experienced a diabetic coma.A relative of Morsi told HRW in 2015 that a prison nurse or doctor usually checks the former president's blood pressure and sugar level every few days but provided no other healthcare.The relative said the authorities had never allowed the family to deliver any food or medicine - as most relatives of prisoners do to supplement the often dangerously meager provisions in Egyptian prisons - and that Morsi had been buying his own insulin using money deposited by his family.The authorities had also denied Morsi any access to newspapers, television and phone calls, the relative added.In October 2018, Morsi's son, Abdullah, was arrested days after he told The Associated Press news agency in an interview that his father's health had deteriorated due to prison conditions and that the family was rarely allowed to visit.Abdullah said he was seeking more visitation rights and better healthcare for his ailing father.