More than 1,540 gardaí have been trained in the use of roadside breathalysers since mandatory alcohol testing was introduced last year.
This brings to over 3,700, or close to one in four of the over 13,100-strong force, the number of gardaí trained to use this equipment.
Because a significant number of gardaí are in management or assigned to special units and not directly involved in front-line road traffic enforcement, the percentage of active gardaí trained to use this equipment is likely to be far higher.
A breakdown of how many gardaí - including the 920 members of the Traffic Corps - are engaged in drink-driving enforcement was not available from An Garda Síochána yesterday.
Data obtained from the Medical Bureau of Road Safety (MBRS) also shows that the number of roadside breathalysers in use had increased to almost 500 by May this year, compared with just 40 at the end of 2005.
The MBRS also said that in the 12 months to May 2007 some 267 gardaí were trained in the use of the station-based intoxilysers, bringing to 2,019 the number trained in the use of this equipment. There are 64 machines across the Republic.
However, the MBRS has also revealed that more than 450 gardaí are now awaiting training in how to operate station-based intoxilysers.
Roadside breathalysers are used as an indicator of whether a driver is over the limit. For a prosecution, a driver must give a blood sample, urine sample or breath test using a station-based intoxilyser.
Head of the MBRS Prof Denis Cusack said a number of training programmes for the station-based intoxilysers had been deferred this year, due to the additional workload created by the introduction of random alcohol testing.
"The priority became the programme. More than 2,000 gardaí are trained as operators of the evidential breath testing system, meaning you would have about 30 officers trained to use each machine.
"We would recommend that there are no fewer than 15 trained gardaí for each machine, so that is a very significant amount of gardaí trained."
Prof Cusack said additional training courses were being planned for the autumn, to clear the waiting list for training in the use if the intoxilyser machines.
He added that random alcohol testing has resulted in a 27 per cent rise in the number of samples being sent to the MBRS for analysis. "Up to the end of April there has been a 27 per cent rise in the number of samples. Drug samples have also gone up."
Fine Gael transport spokeswoman Olivia Mitchell said An Garda Síochána should consider mobile units for evidential breath-testing.
"They do this in Australia. Otherwise you are taking gardaí off the street, driving 20 or 30 miles to a station with an intoxlyiser machine, which undermines the purpose of random breathtesting," she said.
"With this system there is a real risk, and it may be happening already, that by the time you get to a station with a machine and someone trained to take a sample you may have passed the time in which you can detect the alcohol," she added.
Garda Representative Association president John Egan said more gardaí need to be trained in the use of the intoxilyser.
He said he was aware of instances where a driver arrested on suspicion of drink driving was taken to a Garda station but there was not a garda trained in the use of an intoxlyser available.
"Now, I'm not aware of any prosecutions falling as a result, and in the cases I know of a solution was found but we need more training on new equipment and also on new laws."
Prof Cusack said An Garda Síochána has not made a request to increase the number of station-based intoxilyser machines.
