120 serious complaints made by prisoners since beginning of last year

Prisoners have made more than 120 serious complaints since the beginning of last year.

But only eight were upheld or partly upheld.

There are six categories of complaints under the Irish Prison Service's complaints system.

The most serious are category A, which are investigated by outsiders.

According to details released under the Freedom of Information Act, prisoners made 80 of these last year and 42 in the first seven months of this year.

The highest number was in Midlands prison, with 23.

Assaults accounted for almost half of the complaints, at 58, while there were 33 allegations of mistreatment in jail.

There were also 17 sexual incidents reported to prison authorities and seven allegations of racial abuse.

Of the complaints made, only six were upheld and two were partly upheld.

Gabriel Keaveny, assistant general secretary of the Prison Officers' Association, said: "The vast majority of those complaints are vexatious."

"We believe that the statistics actually support our view and what happens, in essence, is it's making our work very, very difficult indeed.

"We welcome independent investigations, however, we would say that where complaints of a vexatious nature are made, then prison officers should be supported in the work that they're doing by management of the prison service."

The Irish Prison Service says all prisoners have the right to make a complaint at any time and all complaints are treated seriously.