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

The 79-year-old was Eritrea's longest serving minister of finance, but he was removed from his role in 2012 following clashes with President Isaias Afwerki.

Six years later, he was jailed after releasing a book where he described the president as a "dictator" who needed to resign.

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

The government also rarely shares where the bodies are buried but Mr Berhane's family have heard there is a plan to bury him in Asmara Patriots Cemetery. Only veterans of the Eritrean independence war, like Mr Berhane, or members of the national service can be buried there.

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

He was never brought before a court of law.

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

Political parties, civic organisation and independent media are all banned.

The UN and human rights groups have long accused the Eritrean government of gross human rights violations, including torture, forced disappearance and the imprisonment of tens of thousands of people in inhumane conditions.

Mr Berhane's fall-out with President Isaias began during the former's 12-year tenure as finance minister, in which he urged Mr Isaias for transparency on the country's budget. The budget is still inaccessible to the public today.

In 2012, Mr Berhane was removed from his post and sidelined from politics.

Three years later he secretly wrote a two-volume book named My Country, and sent it abroad to be published.

Alongside calling his old boss a dictator and demanding he resign, Mr Berhane used the book to challenge Mr Isaias to a debate on national television.

He also called for the reinstatement of the national assembly - Eritrea's parliament - which had been dissolved by the president in 2002. To this day, there is still no legislative body to hold the government accountable.

In 2018, after Mr Berhane had published My Country, he was detained and imprisoned in an unknown location.

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