The growth in drug use in Northern Ireland last year caused delays in providing pivotal forensic information for prosecutions, it has been revealed.
Scientists struggled to analyse double the number of manageable drugs submissions from police, with a rising number of seizures and the increasing popularity of new so-called designer substances partly to blame, a report said.
The Carrickfergus-based Forensic Science Northern Ireland (FSNI) agency scientifically examines drugs for police investigations, part of a range of services like DNA testing which it provides.
Funding from the police service, FSNI's primary customer, has been frozen amid wider public spending pressures and some of the drugs were sent on to England for analysis.
The FSNI annual report said: "Drugs submissions ran throughout the year at approximately twice the agency's capacity.
"More analyses, coupled with much more complexity in the analyses, have inevitably meant backlogs in the provision of what is often a pivotal piece of information in relation to prosecutorial decisions."
In 2011/12 the number of police drug seizures in Northern Ireland increased by a tenth from 3,564 in 2010/11 to 3,920 in 2011/12, a PSNI report said.
Herbal cannabis, cocaine and Ecstasy were the most common types detected.
There were more than 3,000 seizures of mephedrone, the former "legal high" linked to a number of deaths.
FSNI chief executive Stan Brown said: "The growth in drugs use and the rise of so-called 'designer' drugs have also created a significant increase in demand and complexity versus capacity in the drugs and toxicology sections. This has inevitably led to backlogs."
The FSNI employs around 200 staff, two-thirds of them scientists with expertise in specialities ranging from firearms and explosives analysis to fingerprint recording, DNA and tests linked to road traffic accidents.
"There could be significant potential for FSNI to streamline its analyses, thus reducing unit costs and increasing output rates," the report added.
"Over the next number of years, the agency will adopt a lean approach to reviewing its analytical technologies, processes and flows."
According to Maura Campbell, a deputy director at the Department of Justice, a new rapid analysis process for cannabis by FSNI scientists has yielded positive early results.
Since November 19, the agency has adopted a new target to have 80% of cannabis-only cases processed within 30 days using the new rapid analysis process.
Ms Campbell last week told a Stormont committee: "In the space of the first two months, it has actually exceeded that target."
It met the target in 95% of cases, 53 out of 56. The average time taken reduced to 25 days compared with the target of 80 under the previous process.