PARIS, Jan 29 (AFP) - Smuggled African historic art and archaeological objects of incalculable value, said to be enough to fill a museum, were put on show by French customs Saturday after being seized on their way from Niger to Belgium.

Some 845 items, ranging from dinosaur teeth to neolithic arrow heads and ancient pottery, were intercepted at Paris's Charles de Gaulle airport on January 6 by customs officers searching for drugs.

The smugglers themselves remain at large, pending the issue of arrest and search warrants.

The consignment, totalling half a tonne, covers "virtually the whole of Africa's history and prehistory," said Marie-Helene Moncel, a researcher and expert at France's natural history museum.

It includes 668 stone objects, mainly neolithic, dating from 8,000 to 6,000 BC but some going back to 1.6 million years, as well as dinosaur fossils more than 70 million years old.

Other items were 29 pieces of pottery vessels and nine terracotta figurines from the Bura civilisation of southwestern Niger which flourished from the second to the 11th centuries AD.

Such objects are on the International Council of Museums' list as being frequently looted and are banned from export.

Xavier Vuillaume, a customs officer who made the seizure, said he was astounded by the haul, ironically because the plane's cargo manifest told the truth.

"The customs declaration mentioned African art objects, which can be used as cover for drugs, or protected species or things of that nature," he said.

Moncel said the archaeological damage was enormous, as the objects had been looted from their original sites, so could not be properly dated or studied to the best advantage.

Their historical value was still "incalculable," she added, as was their commercial value, though that depended on the demand.

French customs said the search for those behind the traffic could not begin without the necessary international warrants from Niger which were still awaited.

France's Budget Minister and government spokesman Jean-Francois Cope hailed the seizure, adding that all the objects, which he described as "enough to fill a museum", would be returned to their country of origin.

They were "the legacy of humanity", he said, and the unidentified smugglers faced heavy fines and prison sentences.