GUANTÁNAMO BAY IS the most expensive prison to hold captive in the world – with each inmate costing $800,000 (€588,000) to keep annually.

The cost of holding a captive at notorious detention centre is more than 30 times the cost of imprisoning a person in the United States mainland, the Miami Herald reports.

Several factors contribute to the staggering bills at Guantánamo – staff numbers are huge, for example: as well as guards being employed at the site there are also lawyers, interrogators, linguists, intelligence analysts, federal agents and contract laborers working at the facility.

With so many employees living on site comes the need for a range of amenities, namely: housing quarters, dining rooms, a chapel, mental health services, transportation and security services, a mini-mart, a movie theatre and a newsletter facility.

The Bellingham Herald notes that guards serving at the facility are paid the same wage as combatants in war zones, and that 171 prisoners detained there receive $38.45 worth of food each day.

Added to the cost of housing, feeding and caring for both staff and prisoners are the practical problems of sourcing supplies. Former commander at the centre, Greg Zanetti, told journalists that everything ”from paper clips to bulldozers” – has to be shipped in to Guantánamo.