In an unprecedented move, Eritrean bishops in the Orthodox church have excommunicated their former patriarch, Abune Antonios.
Antonios, who was the head of the church until 2006, was accused of heresy in a statement signed by six bishops.
He has for a long time been a critic of the government and was deposed and put under house arrest 13 years ago.
His followers accuse the government of interfering in church affairs.
He was deposed in 2006 after he refused to excommunicate 3,000 members of a Sunday school movement.
But analysts believe he was deposed so the Eritrean government could have full control of the Eritrean Orthodox Church, reports BBC Tigrinya’s Teklemariam Bekit.
When he was deposed he was put under house arrest, where he remains.
In April he secretly filmed a video where he objected to the church being led by layman Yoftahe Dimetros.
The letter from the bishops said that his recent activities made the church realise that “his repentance was not genuine and decided to excommunicate him”.
“His name should never be mentioned and remembered and those who do will be punished severely,” the letter added.
What is heresy?
The Oxford English Dictionary defines heresy as “religious opinion or doctrine maintained in opposition, or held to be contrary, to the ‘catholic’ or orthodox doctrine of the Christian Church”.
It’s a controversial term with negative connotations as critics say it is an example of religious intolerance and repression and used to silence free discussion.
Thousands were burned at the stake for heresy in the 11th and 12th Centuries in Europe for beliefs the Roman Catholic church deemed to be in contradiction with their teachings.
In 1478 the Spanish Inquisition was established to identify heretics among those who had converted from Judaism and Islam to Catholicism. Over three centuries thousands were executed and hundreds of thousands prosecuted for heresy.
Orthodox Christians make up one of the main religious groups within Eritrea.
Only four religious groups are allowed to operate in the country; the Eritrean Orthodox, Evangelical Lutheran and Catholic churches, and Sunni Islam.
In June the Catholic church said that the government had closed down all their health centres after the church called for reforms to stem the tide of migration to Europe.
Eritrea became an independent state in 1993, and has been under President Isaias Afwerki’s rule ever since.
His critics accuse him of leading a repressive state, but his supporters deny this.