A third anti-government protester has died in police custody in Egypt due to what opposition and groups have denounced as “systematic and deliberate” medical negligence by prison officials, Press TV reports.

The protester, identified as Ramadan Seddiq, was pronounced dead inside his prison cell on Sunday in the southern city of Sohag. He was reportedly suffering from cancer.

A day earlier, two other anti-regime protesters had died at the Torah prison hospital north of the capital, Cairo.

Death of a Brotherhood leader

Separately, Ahmed Hussein Ghozlan, a Muslim Brotherhood leader, reportedly died in his cell in el-Aba’diah Prison in the northern Beheira Province on Saturday after prison authorities purportedly denied him medication.

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

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

The ECRF said 143 of the deaths were due to “deliberate and systematic medical negligence” by prison authorities.

Muslim Brotherhood members and supporters have faced a violent crackdown by the Egyptian government since Morsi’s ouster, which was led by then military chief and current President Abdel Fattah el-Sisi.

Thousands of government opponents, mainly from the Brotherhood, have been imprisoned; while hundreds, including Morsi himself, have been sentenced to death.

Hundreds of others have been killed in street protests.