Image caption Academic Marisa McGlinchey wrote Unfinished Business: The Politics Of Dissident Irish Republicanism

The NI Prison Service has commissioned a review of which books prisoners are allowed access to in its jails.

The move came after it emerged that a book on dissident republicans had been banned from Maghaberry Prison.

A number of copies of the book were brought in by visitors to be given to inmates, but prison authorities refused permission for them to be passed on.

The Prison Service said it had a duty to maintain a neutral environment for prisoners.

The book in question was Unfinished Business: The Politics Of "Dissident" Irish Republicanism, by the academic Marisa McGlinchey.

Its publishers say it discusses the development of dissident Irish republicanism and considers its impact on politics throughout Ireland since the 1980s.

The publishers say it is based on a series of interviews with more than 90 "radical republican activists from the wide range of groups which make up 'dissident' republicanism".

The BBC asked the Department of Justice three questions:

Is there a list of books prisoners can have access to?

If so, how is that list compiled?

In this specific instance, why was this book not allowed to be sent to a prisoner?

In response, Ronnie Armour, Director General of the Prison Service, said: "The Northern Ireland Prison Service has a duty to maintain a neutral environment for prisoners, visitors and staff.

"This can be particularly challenging and will mean some items may not be permitted into our prisons.

"There is no list of books not permitted, and decisions are taken on a case by case basis.

"These decisions can be difficult and are often finely balanced.

"Therefore I have commissioned a review into our current practices."

Mr Armour has also contacted Dr McGlinchey to discuss the apparent banning of her book from the prison.

Dr McGlinchey said she felt her work had been undermined by the Prison Service's approach, and would be asking Mr Armour to explain why prisoners were not allowed to receive copies of the book.

Her solicitor Darragh Mackin said it was a "dangerous precedent to adopt a policy which meant that certain books could be banned from Maghaberry Prison without any justifiable reason".

Mr Mackin said he welcomed the news that the head of the Prison Service had commissioned the review and said he was aware of other instances where prisoners had been denied access to academic works.