IRELAND'S longest-serving detective, Assistant Commissioner Martin Donnellan, who won a bravery award when he once - unarmed - arrested the country's most dangerous armed criminal, last week lost a High Court action aimed at overturning a rule that forces senior policemen to retire at the age of 60.Donnellan, whose own retirement took place a month ago, said he took the action because he believed Irish policemen should be allowed continue serving until the age of 65 as is common throughout the European Union.He said he did not pursue the case for financial gain, but because he believed he had much more to offer the police force.Donnellan claimed the law requiring him to retire at 60 is ageist, irrational and contrary to changes in life expectancyHis challenge was to a regulation introduced in 1996, lowering the retirement age for assistant commissioners from the age of 65 to 60. In opposing the case, the State argued the lower retirement age was necessary to ensure talented younger people could move through the ranks of the Garda. The state also claimed that restoring the age to 65 would create a blockage at senior level. In his judgment, Justice Liam McKechnie said he was satisfied the 1996 regulation was introduced as part of a policy aimed at motivating the force, freeing up positions in higher ranks for individuals whose ambition was to progress through the Garda and allowing senior management to promote particularly talented people earlier than previously might have been expected. The judge said the aim of the 1996 change was to provide for a more efficient and effective police force and the government of the day was entitled to make that change. It was not the function of the court to encroach on policy of the government in this respect or to encroach on the management of the Garda. The judge added that while there was no dispute that Donnellan would be a loss to the force, that factor applied in many areas of life. He further noted that retirement will not place a financial penalty on Donnellan, who will receive a gratuity of more than $315,000 along with an index-linked pension of $110,000 per annum.Donnellan, who at one stage was in charge of the National Immigration Bureau, said he was disappointed with the judgment."I took this case on a point of principle. I took it, having got legal advice, because the Home Office and the association of Chief Police Officers in Britain did extensive study in the light of the EU directive on ageism, and they concluded that police up to the rank of chief inspector should serve until 60 and officers above that rank until 65."He said there was absolutely no research done on the issue by the Department of Justice in Dublin or by the Garda force.He added that while in charge of the National Immigration Bureau he met many officers from police forces across Europe who could not understand why senior Irish officers were retired at 60.