The Secretary General at the Department of Health described as "completely unacceptable" a request for detailed information on primary care centres from the Minister for Health's assistant last year.

Ambrose McLoughlin said the request raised the most serious governance issues which had to be dealt with by James Reilly, documents released to RTÉ under Freedom of Information show.

Tom O'Leary, who was Mr Reilly's personal assistant at the time, sent an email on behalf of the minister seeking a detailed progress report on the centres.

The request came two months after a junior minister resigned following controversy over the locations of the centres.

Mr O'Leary wanted to find out what leases had been issued, details of projects under negotiation, the terms agreed, the planning granted, the capital value of the projects and the numbers that would be employed.

But following the Secretary General's sharp response, Mr O'Leary sent another email the following day to say he had misunderstood the minister.

He said Mr Reilly had not sought this "certain information" and in fact only wanted a visual representation of the progress of the centres nationwide.

Mr O'Leary, who resigned from his position last January, then apologised and said he was incorrect in suggesting the minister had sought that level of detail.

A spokesperson for Mr Reilly said the former assistant had made a mistake in seeking these details which would not be appropriate for a minister to see.

He said the assistant soon realised he had made a mistake and had misunderstood Mr Reilly.

The matter was then clarified with another email.

Sinn Féin health spokesperson Caoimhghín Ó Caoláin praised the Secretary General for refusing the information.

He said it would have been wrong to disclose commercial detail like that requested.

Mr Ó Caoláin also accused the Minister for Health of involving himself too much in the primary care centre project.

Deputy Denis Naughten of the Reform Alliance said Mr Reilly must quickly clarify what information was sought and why it prompted such a strong reaction from the Secretary General.

Former minister of state with responsibility for primary care Róisín Shortall resigned in September 2012 after 15 primary care centre locations, including two in Mr Reilly's constituency, were added to a list of care centres due to be built using a public private partnership (PPP) agreement.

Despite appearing on the PPP list, the Balbriggan centre is being developed by lease arrangement with the developer, Rhonellen Developments.

The documents show that the Health Service Executive is also hopeful that Swords will be developed using the lease option.

The final list of 16 primary care centres to be built by PPP was published by the HSE earlier this month.

Boyle in Co Roscommon is the only one of the 15 locations added last year that made the final list.