Gardaí may not be able to detect all disqualified drivers on the roadside because the database they rely on is incomplete, it has emerged.

Road Safety Authority Chief Executive Moyagh Murdock admitted it was "not acceptable" that it can take several weeks before banned drivers are recorded on a database which gardaí can access.

The National Vehicle Driver File, which is used by gardaí to detect disqualified drivers, relies on information provided by the Courts Service, but it can take several weeks before court convictions are registered.

Speaking on RTE's This Week, Ms Murdock said: "There is a time lag before the driver file is updated, and that is not satisfactory".

She said records were uploaded manually, but this would move to an "automatic feed" by the summer.

She was responding to concerns raised by the road victims group PARC, and questions raised by Independent TD Tommy Broughan.

Last year it emerged that there were large discrepancies between the number of disqualified drivers recorded by the Courts Service when compared to the figures on the National Vehicle Driver File.

For the years 2016 and 2017 there was a difference of 1,075 drivers between the two databases.

Asked about this, Ms Murdock said she was satisfied that the numbers of disqualified drivers on the National Vehicle Driver File are accurate.

"But there are differences the way the Courts Service records their disqualifications is different from the way the RSA and the Department of Transport record," she added.

"We are recording the effective date of a disqualification, where as the Courts Service would record the day they appeared in court."

She said a due diligence procedure is being carried out by the RSA on these discrepancies.

However Ms Murdock admitted there were a small number of drivers who cannot be matched between the two systems.

She said in this situation the RSA could not apply a disqualification to the wrong driver record.

"We must be satisfied that the licence holder that incurred the disqualification is the person that we're applying the disqualification to."

However she said it was only a "very small number of people" in that situation.