The Director of Public Prosecutions has expressed deepening concerns that the number of cases her office can examine will fall due to cutbacks.
Claire Loftus, who took over the role last November, said lawyers in the division are fully stretched due to increasingly large and complex cases.
"We have largely managed to maintain the same overall rate of throughput as achieved in 2010 and 2009. I am increasingly concerned however that it will not be possible to sustain this in the coming years," she said.
"The expenditure of the office is essentially demand-led as we do not have control over the level of crime or the number of prosecutions we must bring."
The DPP's annual report also revealed the office received 12 requests last year for explanations as to why a decision was taken not to prosecute over a death.
"We have already learned by experience that the process of giving reasons in cases involving a fatality which has been ongoing since 2008 has proved to be very resource intensive and this will be a significant factor in any expansion of this work, which is required under this directive, in the future," Ms Loftus said.
The move to elaborate on reasons for not prosecuting began in October 2008 with the family or household of the victim of a death allowed to apply for information on why the case was dropped. Since then a total of 33 requests have been received, with 79% relating to fatal road traffic cases.
The DPP revealed that in 24 cases detailed reasons where given to relatives; another five requests were refused by the office; one family withdrew their request for information; and decisions are pending on three others.
Elsewhere, the report showed the office received 16,128 files relating to the prosecution of crimes in 2011. It peaked in 2008 at 16,144. It took in 9,276 files where a decision on whether to prosecute had to be taken and these involved 12,728 suspects. Some 37% were not brought to court for prosecution.
The report said that of the 4,751 cases not prosecuted 75% were dropped because of insufficient evidence and among the others 194 were found to be not in the public interest; 21 dropped on sympathetic grounds; and 247 because the injured party withdrew the complaint.