Mobile phone and drug seizures increased by 20% last year - but no contraband was found in Loughan House in Blacklion, Co Cavan.
Loughan House was one of three prisons in which no contraband was discovered last year, the other two being Arbour Hill in Dublin and Shelton Abbey in Co Wicklow.
Across the country's 12 prisons, 1,369 mobile phones were discovered - an increase of 19% on 2020 levels.
There's also been a 21% increase in the number of drug seizures in Irish prisons last year, with 1,518 incidents recorded where prison staff detected illegal drugs.
The Irish Prison Service says there has been an increase in the number of "throw overs", where contacts on the outside attempt to throw mobile phones and drugs into exercise yards.
However, the prison service added that "prison staff have been able to identify and intercept many of these throw overs".
