Half of all Garda Assistant Commissioners have retired or will retire by the end of the month, including the most senior officers in charge of the Anglo Irish Bank investigation.

Assistant Commissioner Michael Feehan, the officer in charge of policing Dublin, is the latest high ranking garda to announce his early retirement.

His departure means half of the country's assistant commissioners, the third highest rank in the force, will be gone by the end of the month.

The Association of Garda Sergeants and Inspectors has said that 51 senior garda officers have not been promoted in the past six months despite vacancies in these ranks all over the country.

The association has said that the managerial and supervisory ranks in the force are being "decimated" by retirements across the country.

There will be 19 Chief Superintendent and 44 Superintendent posts that will have to be filled.

This includes the Chief Superintendent and Superintendent in the Fraud Squad, the two most senior officers in charge of the investigation into Anglo Irish Bank.

Minister for Justice Alan Shatter has said that he will very shortly bring proposals to Government to have the appropriate vacancies filled.

Mr Shatter said that when the appropriate vacancies had been filled, additional appointments may also be made.

The minister did not say how many senior garda jobs might be involved.

He was speaking in Belfast following a meeting with his counterparts in Northern Ireland and Scotland.