Berhane Abrehe, a former Eritrean finance minister and fierce critic of the country’s president, has died in prison, his family said.

The 79-year-old was Eritrea’s longest-serving finance minister, but was removed from office in 2012 after clashes with President Isaias Afwerki.

Six years later, he was imprisoned after publishing a book in which he called the president a “dictator” who must step down.

His family told the BBC that authorities, who rarely confirm the deaths of senior officials in custody, had informed them of Mr Berhane’s death.

The government also rarely discloses where bodies are buried, but Mr Berhane’s family has heard that there are plans to bury him in the Asmara Patriots Cemetery. Only veterans of the Eritrean War of Independence like Mr Berhane or members of the military service can be buried there.

His body has not yet been released, his family said, and it is unclear when and how exactly Mr Berhane died.

He was never brought to trial.

President Isaias has ruled the East African country since his victory in the war of independence against Ethiopia in 1991 without holding national elections.

Political parties, civil organizations and independent media are all banned.

The UN and human rights groups have long accused the Eritrean government of serious human rights violations, including torture, enforced disappearances and the detention of tens of thousands of people in inhumane conditions.

Berhane’s dispute with President Isaias began during the latter’s 12-year term as finance minister, when he demanded transparency from Isaias regarding the state budget. The budget is still not accessible to the public.

In 2012, Mr Berhane was removed from his post and pushed out of politics.

Three years later, he secretly wrote a two-volume book entitled “My Country” and sent it abroad for publication.

Berhane not only called his old boss a dictator and demanded his resignation, but also used the book to challenge Mr Isaias to a debate on national television.

He also called for the reinstatement of the National Assembly, the Eritrean parliament, which the president dissolved in 2002. To date, there is no legislative body that could hold the government accountable.

In 2018, after Mr Berhane released “My Country,” he was arrested and detained at an unknown location.

At that time, his wife was already in prison, although no reason was given. She was released in 2019.

One of Mr Berhane’s sons, who was imprisoned at the same time as his mother, had previously described his family’s ordeal to the BBC.

“I live with a faint glimmer of hope that my father, who has health problems, (will one day be released from prison),” Efrem Berhane said in 2020.

The 31-year-old, who lives in the United States after fleeing Eritrea, asked: “How can people be kidnapped by a government and disappear for years? Why do people show such cruelty to a fellow human being?”

However, some people were imprisoned for even longer.

In September 2001, 11 senior ministers and generals who were part of a group called the “G-15” were arrested after criticizing the president. The group – which also included three former foreign ministers, an education minister and a former chief of staff of the armed forces – has not been seen since.

In Eritrea, political prisoners are often forbidden from having contact with the outside world.

In February, Ilze Brands-Kehris, United Nations Assistant Secretary-General for Human Rights, said that “impunity” for human rights violations continued in Eritrea.

“Our office continues to receive credible reports of torture, arbitrary detention, inhumane prison conditions, enforced disappearances, restrictions on freedom of expression, association and assembly,” she said.

Mr. Berhane was born in Eritrea in 1945 and earned a master’s degree in economics from a U.S. university before joining Ethiopia’s struggle for independence.

He is the father of four children.