INMATES in the country's prisons amassed a phone bill of more than €1.05m last year, according to the Department of Justice.

The prisoners, who are entitled to several phone calls a week, racked up an average bill of €290 each ringing their family, friends and solicitors.

The largest expenditure was at the Mountjoy complex, which includes Mountjoy itself, the training unit, St Patrick's and Dóchas – where spending came to €271,399.

Prisoners are generally allowed four phone calls a week and sometimes more, depending on their circumstances and the discretion of prison management.

In recent years, those phone calls haven't been enough for most inmates and thousands of mobile phones have also been seized behind bars.

At some jails, prisoners are asked to contribute towards the cost of their phone calls by buying call cards but in many prisons, that system has not been implemented.

"Allowing them to make phone calls to family and friends is in many ways a wise investment because it can have a calming effect on some prisoners," said one prison officer said. "If they were completely isolated from their family, it would cause trouble."

The costs have also risen because of the numbers of non-national prisoners now behind bars, particularly those held on immigration offences or awaiting deportation.

The single biggest phone bill was at Cloverhill Prison, the state's main remand centre, where €211,299 was spent on calls. A €152,756 phone bill was run up at the Midlands Prison.

In high-security Portlaoise Prison, whose inmates include John Gilligan and Brian Meehan, the cost of calls in 2008 was €86,839.

The prisoners' phone bill was part of a €2.25m spend on prison telephone costs during 2008, according to departmental figures.

While €1.05m was spent by the jails, primarily on prisoners' phone calls, another €1.2m was spent on what are known as "central costs".

A general telephone bill of €738,749 was accrued by the Irish Prison Service.

Another €421,999 was spent by the Irish Prison Service at its headquarters in Longford while the little-known Prisons Disaster Recovery site spent €36,645.

Mobile phone costs in the order of €217,000 were also amassed, primarily by senior civil servants and management.