Minister for Justice Michael McDowell has ordered an inquiry into how a well-known criminal was able to phone a live radio show from his cell.
The inmate - who is serving nine years in Portlaoise prison - used a mobile phone to take part in a debate on RTÉ's 'Liveline' programme yesterday.
Mr McDowell said today that the problem of materials being smuggled into prisons was on the increase and the matter was being investigated.