An extraordinary stand-off has emerged between the State’s official statistics body and the data protection watchdog over a plan by the Central Statistics Office (CSO) to force mobile phone network providers to hand over roaming data about tourists and Irish residents travelling abroad.

Communications between the Data Protection Commissioner (DPC) and the statistics office over a period of almost nine years up to late last year reveal the statistics body wanted to compel mobile operators to transfer to it on an ongoing basis the details of phones or users roaming on the networks, as well as the dates and times of their calls.

The commissioner objected on the grounds there was no legal basis to allow the CSO obtain such data and on the grounds it would be a serious interference with people’s privacy rights.

The statistics office first wrote to former commissioner Billy Hawkes in 2008 to say the data on international mobile phone roaming usage “may significantly enhance our statistics on tourism and international travel”.

In its response, the commissioner’s office noted the transfer of information such as a unique handset ID would constitute personal data. It was of the view that the Statistics Act could not oblige the mobile operators to provide such information.

Identify individuals The conflict centres on whether the information transferred by the providers, even without names and addresses, can identify individuals.

In a case last year, the Court of Justice of the European Union held that traffic and location data was liable to allow “very precise conclusions” to be drawn about the private lives of individuals.

The mobile network operators also expressed concern about the proposal, fearing that releasing the information would put them in breach of the law.

In 2012, the CSO had a statutory instrument drawn up by the attorney general’s office to allow it collect the mobile data, which it envisaged would be signed by then taoiseach Enda Kenny.

In August 2013, legal adviser to commissioner Garrett O’Neill wrote to John Dunne of the statistics office expressing concern about the draft regulation. He said that even though it would give legal effect to the extraction of the data from mobile phone operators, that the project was “disproportionate and not something in which the DPC can stand over”.

The “extraordinary” project would, in effect, “track the movements of visitors to this country and will in turn, affect tourists’ privacy rights, in that their entire holiday will have been recorded and analysed, albeit anonymously”.

Mr O’Neill said the office’s policy was that “nobody should have access to mobile phone data except in unique justifiable circumstances such as the gardaí needing the data to investigate a serious criminal offence”.

“Should the proposed order proceed then the commissioner will be publicly stating through his annual report or otherwise that while recognising that the legal circumstances exist for the project to happen, he is strongly objects to same because of the interference in the privacy rights of visitors to this country,” Mr O’Neill wrote.

Objections raised The email prompted a letter from the director general of the statistics office, Pádraig Dalton, to Mr Hawkes saying he was “particularly concerned with the nature and language of the objections raised and would be very distressed to hear them aired in public”.

He said the comments made by the commissioner’s office “appear to implicate the CSO in the surveillance of tourists”.

A spokeswoman for current commissioner Helen Dixon said at the weekend the office was not aware of any imminent proposal to sign into law a statutory instrument and that if the CSO planned to do so, it would expect to be consulted.