A leader of Egypt’s Muslim brotherhood movement has died in jail due to what human rights groups call “deliberate medical negligence” by prison authorities.

Media outlets close to the political group said Saturday that Ahmed Hussein Ghozlan had died earlier in the day inside his cell in el-Aba’diah prison in the northern Beheira Province.

The 52-year-old was arrested last March, on charges of participating in anti-government protests, as well as possessing booklets belonging to Muslim Brotherhood.

A local group advocating the rights of prisoners in Beheira said officials in el-Aba’diah facility should be held responsible for the death of the political activist.

The Egyptian Commission for Rights and Freedoms (ECRF) says so far it has documented nearly 270 deaths inside detention facilities in Egypt, since the former president Mohamed Morsi was overthrown in a coup in July 2013.

The ECRF also says 143 of those deaths were due to prison authorities’ “deliberate and systematic medical negligence.”

Meanwhile, Egyptian judicial authorities have sentenced 300 opponents of the military-backed government to jail terms ranging from three to 10 years.

The Zaqaziq criminal court in the Nile Delta Province of Sharqiya, northeast of the capital Cairo, on Saturday sentenced 300 people, mostly Muslim Brotherhood supporters, to jail.

The court sentenced 269 protesters to 10 years in jail each. It also sentenced 31 others to three years each.

The defendants were sentenced on five alleged charges that included membership in the outlawed Muslim Brotherhood group.

The defendants were also charged with allegations of possessing weapons, inciting and committing violence in al-Sharqiya Province. They were also charged with holding unauthorized protests.

The military-backed government of former army chief and now president, Abdel Fattah el-Sisi, led the army overthrow of the country's first democratically-elected president Mohamed Morsi from presidency over two years ago. Morsi hailed from the Muslim Brotherhood.

Since Moris's overthrow thousands of government opponents, mainly from the Brotherhood, have been handed jail terms by civilian and military courts. Hundreds, including Morsi himself, have been sentenced to death in mass trials.

Hundreds of others have been killed in street protests, and many have been killed while in police custody.

This as earlier on Saturday, an Egyptian court has postponed a verdict in the case of an al-Qaeda linked militant cell for "security reasons."

The Cairo criminal court adjourned to August 10th a ruling concerning the "al-Zawahiri terrorist cell." It cited "security reasons" for the delay.

Egyptian authorities fear a rise of terror activities by ISIL and al-Qaeda-linked militants ahead of the official inauguration of the new Suez Canal project on August 6.

Mohamed al-Zawahiri, the brother al-Qaeda leader Ayman al-Zawahiri, and sixty seven other defendants, are accused of forming and managing a terrorist group responsible for attacks against army and police units in Egypt.

All defendants, of which 54 were present in court, and 14 are being tried in absentia, are accused of establishing a terrorist organization in affiliation with al-Qaeda.

They were referred to criminal court by Egypt's slain top prosecutor in April 2014.

The prosecution had accused Zawahiri of leading a militant group during the reign of Morsi. Zawahiri was arrested about six weeks after Morsi's overthrow.

Back in January, al-Zawahiri and several defendants in the case were sentenced to a year in prison on charges of insulting the judiciary during the trial.