Protesters outside the Moriarty Tribunal in July 2000
The report declared that corruption was a central theme of life in Ireland and that human rights standards were below international levels.
Commissioned by the British-based Joseph Rowntree Charitable Trust, the report said: "Ireland is now regarded as one of the more corrupt European states - and to have lost a considerable amount of foreign investment because of its international reputation."
The report, prepared by independent social researcher Brian Harvey, was published on Thursday following a baseline study almost a decade ago.
It coincided with continuing proceedings at tribunals of inquiry into payments made to Irish politicians - including three-times former Prime Minister Charles Haughey - and alleged planning irregularities also implicating senior political figures, as well as a number of scandals.
But Mr Harvey found that while the continuing investigations had "done much to determine the nature of corruption, changes to improve the political and administrative system have been minimal".
"The fact that the problem is systemic has yet to be fully recognised. It is a serious gap in the modernisation of Irish governments," he added.
Mr Harvey called for the establishment of a special independent body to monitor corruption and cronyism in public life.
'Widening inequality'
His report also said the Irish Republic had "widening levels of inequality, extraordinarily low levels of investment in public services, and a depressing record on environmental protection".
He said that despite years of "unprecedented wealth" in the Republic of Ireland, resources had been squandered with many public services, especially health, in a worse state than ever.
The report also said the state was in breach of five international agreements related to the treatment of mentally-ill prisoners.
"It's unacceptable in the face of evidence about the widespread abuse of human rights that many would have characterised as being a feature of the Soviet system many years ago," Mr Harvey added.
Mr Harvey said problems requiring "urgent action" included: