More than £2 million worth of antiquities are illegally exported from Ireland annually in a smuggling trade which has become second only to drug-dealing as the most lucrative crime in the world.
The Law Reform Commission says the £2 million figure is a conservative estimate and it says the Garda is currently setting up a computerised database of stolen objects.
In a major report recommending that Ireland should accede to UNESCO's Unidroit Convention on Stolen or Illegally Exported Cultural Objects, the commission says the need for such an international instrument is "beyond doubt".
The convention is aimed at protecting cultural property by conferring on dispossessed owners - whether states, institutions or private individuals - the right to seek the return of objects stolen or illegally exported from their jurisdictions.
The commission's 187-page report notes that the saleability of cultural objects on the international art market has flourished since the end of the second World War and that this demand had encouraged organised crime in the theft or looting of such objects.
"The last 50 years have seen a proliferation of international declarations, resolutions and treaties - bilateral, regional and universal in scope - which assert the fundamental importance of the protection of the cultural heritage," the report says.
A number of these measures are concerned with the illicit movement across borders of cultural objects, but it says "the continued and almost exponential growth in the illicit trade in art in that same period suggests that they have had only limited success".
However, "a greater consensus has emerged regarding the need to take effective international action to remedy those legal shortcomings which are currently used by international `cultural criminals' to their own advantage". Unidroit is the most recent effort.
The report says cultural objects "have a significance which may be described but not fully understood in purely logical terms". They "nourish our sense of national identity in the broadest sense".
It quotes the judgment of the former chief justice, Mr Thomas Finlay, in the Derrynaflan case which said: "One of the most important national assets belonging to the people is their heritage and knowledge of its true origins and the buildings and objects which constitute keys to their ancient history."
The report notes that the movement of objects results in "the destruction of context" which, for some, is an all-important value. "Decontextualised - taken from the entirety of which they were a component - both the entirety and the individual objects lose significance," it says.
The argument in favour of freedom of movement generally comes from those states "where the art trade is prospering and there is abundant capital in search of investment while at the same time the amount of cultural property available internally may be relatively small.
"On the other side, `exporting states' which have a rich indigenous culture, but may be poor in terms of material wealth, adopt a more retentive approach, attempting to curtail the operation of the free market by means of export prohibitions," the report says.
In South America, between $2 billion and $10 billion worth of art objects are lost each year through theft and smuggling. And though Ireland's losses would not compare with this, "a significant quantity of Irish objects are finding their way on to the international market".
The report notes that it took six years to negotiate the Unidroit Convention, mainly because of ideological differences between those states which favour the free international circulation of cultural objects and others who sought to extend restrictions.
Thus, the convention introduces a regime of "common minimal legal rules" in order to ensure that differences between various legal systems cannot be exploited to the benefit of the illicit trade. It seeks to protect cultural heritage while also facilitating the legal trade in objects.
Unidroit endorses the concept of the "common heritage of mankind", but it also notes the importance of retaining objects in their proper context. It also acknowledges the need for a "multi-faceted approach" to stem the "ongoing impoverishment" of cultural heritage worldwide.
Apart from the increasing demand for art objects and their consequent rise in value, the report says the illicit trade in art is also attributable to advances in technological sophistication and electronic transfer of funds, as well as the ease in crossing international borders.
"These advances compound existing difficulties in detecting illicit activity. In general, police and customs officials are neither adequately trained nor resourced to curb the outflow of art works from their jurisdictions," the commission says.
It suggests that the Unidroit Convention promotes the protection of cultural heritage, both nationally and internationally, "by contributing to debate on the importance of such protection and encouraging states to be more vigilant in regulating and punishing certain activities".
Historically, it says, Ireland was primarily an "importing" country, as evidenced by its great national and private collections of objects from all over the world. But in recent years, the theft of objects from Ireland had "increased dramatically".
The commission recommends that Ireland should make a declaration under the Unidroit Convention nominating the Minister for Arts, Heritage, the Gaeltacht and the Islands as the central authority to which claims for restitution or requests for return should be made. It also suggests that "fair and reasonable" compensation should be available to a bona-fide possessor of an illegally exported cultural object, provided that the possessor neither knew "nor ought reasonably to have known" that the object had been illegally exported.
The commission also recommends that a provision be enacted clarifying that a landowner on whose land archaeological objects are found does not constitute an "owner" for the purposes of the National Monuments Act 1994, unless he or she is the original owner of the object.
