The Government has expressed serious concern about a US court order for Microsoft to hand over emails held on servers in Ireland to US prosecutors, saying it would create significant legal uncertainty about data protection in Europe.
Last week, a US judge lifted a suspension on her order directing Microsoft to turn over a customer's emails, but the software company said it would not release any emails while it appeals the ruling.
Dublin is a major host of data servers, including a massive complex in west Dublin that belongs to Microsoft.
Data Protection Minister Dara Murphy said the Government would be open to a request for the emails under the 2001 Mutual Legal Assistance Treaty, which governs the transfer of information in criminal cases.
But he described as "objectionable" the process being used, whereby a US court was making a direct order about data held in another jurisdiction.
"The possible implications of this ruling are very serious for Ireland and the European Union," Mr Murphy said.
"Compliance with the warrant may result in Microsoft, and any other US companies with operations in the EU which are served with such warrants in the future, being in breach of the Irish Data Protection Acts and the EU Data Protection Directive," he said.
The prospect of emails held in Ireland being handed over has drawn concern from technology companies - fearful of losing revenue from foreign customers worried that US law enforcement might win broad powers to seize their data.
Microsoft in particular was stung by revelations last year by former National Security Agency contractor Edward Snowden and has been at pains to prove to customers that it does not allow the US government unchallenged access to personal data on its servers.
The case appeared to be the first in which a corporation has challenged a US search warrant seeking data held abroad.
Mr Murphy said that he had held talks with the European Commission about the implications of the ruling and would discuss the matter with the US Chargé d'Affaires and the American Chamber of Commerce in Dublin.