Bumper sales of cut-price Tayto Cheese & Onion crisps, bottles of Coca Cola, Jelly Tots, and cigarettes helped profits at the prison service’s network of tuck shops jump to €700,000 last year.

Sales of fake tan and Corona cigars in tuck shops around the country’s prison system contributed to revenues of more than €7.5m.

Justice Minister Alan Shatter has confirmed that the tuck shop at Mountjoy prison is a €1m a year business.