The International Council for Museums has issued a "Red List" of archaeological items being looted on a large scale from Africa and sold on to museums, art dealers and auction houses in Europe and North America.
Icom is hoping the list, which is also being circulated to police and customs officials, will help stop trade in the items.
An Icom spokesman said: "Items from illegal excavations irreparably undermine the historical sources of the continent and those of humankind."
He said the sale of these artefacts in other countries means that the historical context of the places in which the objects were found is wiped out and can never be reconstituted. As a result it may never be possible to learn about the civilisations that produced them.
The eight categories of archaeological items on the Red List include terracotta and bronzes from Ife in Nigeria; terracotta statuettes, bronzes, potteries and stone statues from Niger and Burkina Faso; terracotta from north Ghana; and terracotta and bronzes from Cameroon.
All these objects are protected by national legislation, banned from export and cannot be sold legally under any circumstances.
Icom, based in Paris, said the extent of illicit trafficking in cultural objects has never been greater. It urged museums worldwide to assume a lead role in the fight against the trade and to ensure that they have strict rules on any objects they are offered for sale.
Over the past few months, Icom has signed agreements with the International Criminal Police Organisation and the World Customs Organisation to coordinate the fight against illicit trade in cultural objects.