Unprecedented garda access to the PPS numbers of more than two million road users is being considered by a special Government taskforce, according to documents seen by RTÉ's This Week.

Other measures examined by the multi-agency group include the exchange of PPS numbers between private vehicle buyers and sellers.

Also being reviewed is the linking of car-owners' PPS numbers for each new vehicle registration.

The use of social security numbers to block people with unpaid fines from selling or buying cars or from renewing a licence is also being assessed.

The proposals are contained in the official minutes of meetings of the Criminal Justice Working Group.

The group was set up to consider changes to road traffic crime enforcement, in the aftermath of the penalty points controversy.

The prospect of giving gardaí widespread access to PPS numbers was first raised last April.

The proposal was tabled at a meeting of the taskforce, which is jointly chaired by the Departments of Transport and Justice, as revealed under a Freedom of Information request by RTÉ.

The minutes of that meeting state: "Access by An Garda Síochána to PPS numbers would be helpful in identifying offending drivers."

It said: "An Garda Síochána currently does not have access but further enquiries should be made … in order that penalty points are imposed for all relevant convictions, the outcome of the Group's deliberations should be to ensure that all information held by the State in relation to a vehicle's ownership should be shared across the system."

An Garda Síochána is not presently included on the list of bodies that are allowed to access citizen's PPS numbers.

Currently gardaí have access to the social security numbers of asylum applicants via the Garda National Immigration Bureau.

The membership of the Criminal Justice Working Group includes the Departments of Justice and Transport, An Garda Síochána, the courts service, the office of the Director of Public Prosecutions, and the Road Safety Authority.

The group has not yet issued a final report or made recommendations to Government, although this is imminent.

Access to PPS numbers is primarily the responsibility of Tánaiste Joan Burton's Department of Social Protection.

The department was not included among the Government agencies making up the membership of the group.

A handwritten note written by a Department of Transport official last November includes a proposal to "tap into the Department of Social Protection roll-out of the PPSN identification for all individuals".

It goes on to suggest where there is non-payment of fines, the vehicle record could be "locked down" with the parallel proposal that "outstanding fines have impact on other areas - cannot get licence; cannot sell/buy vehicle".

The group has also floated the proposal that all private car sales should include the transfer of PPS numbers between the seller and vendor.

However, at a meeting of the group on 22 May 2014 it was noted that "requiring the exchange of PPS numbers between private buyers of vehicles could lead to data protection issues".

In another meeting in December, it was noted under "co-ordination of data" that the "solution from a data perspective may not be acceptable from a legal perspective. A draft report from the sub-group is in hand and will be finalised by January 2015. There are some co-departmental and sensitive issues to be resolved".

The minutes also record the aspiration that the Data Protection Commissioner is to be consulted on "vision".

However, a spokesman for the Data Protection Commissioner, Helen Dixon, told This Week the commissioner has not had any contact in the last 12 months on this matter.

"The Department of Social Protection in the first instance oversees and regulates the use of the PPSN so queries should be directed to that body in the first instance. I note from its website that An Garda Síochána is not listed as a registered user of the PPSN," the spokesman said.

"Any such sharing of data would have to be done in compliance with the Data Protection Acts or be specifically provided for in separate legislation, which would have the effect of setting aside the provisions of the Data Protection Acts. Any proposal of this type would require analysis with a complete set of facts and detailed background available," the Data Protection office spokesperson.

A Garda spokesman said the group had not yet finalised its report or made recommendations, and they could not comment at this stage.

The Department of Transport said that correspondence in relation to the committee's work should be directed to the Department of Justice.

The Department of Justice said it was not in a position to outline further details of the group's work this weekend, due to the unavailability of key personnel who are involved in the group, but that it would so at the earliest opportunity.

The Department of Social Protection did not respond to a query from RTÉ in relation to whether Ms Burton was in favour of allowing gardaí to have more widespread access to citizens' PPS numbers.