The illegal ivory trade is expanding, driven by East Asian crime syndicates, according to the wildlife trade monitoring network Traffic.
The syndicates gather ivory in Africa for export to East Asian countries.
The biggest market is mainland China, though there is also significant trade to other countries such as Thailand and the Philippines.
Traffic says there are 92 illegal ivory seizures per month, and the number of large hauls has doubled in a decade.
Its report will be presented to next month's meeting of the Convention on International Trade in Endangered Species (CITES), where wildlife campaigners hope it will put pressure on governments whose countries are used by the traffickers.
"The relevant question is whether CITES is going to crack down or not, whether governments are going to show some political will," said Sue Lieberman, director of the global species programme at WWF which runs Traffic together with the World Conservation Union (IUCN).
"The Asian market is the key. It is thriving again in Thailand, and a lot of Chinese businesses have moved into Africa, for example timber companies, which means more ivory is coming out," she told the BBC News website.
Big hauls up
Traffic bases its report on an analysis of nearly 12,400 records of ivory seizures in 82 countries dating back to 1989 as part of the Elephant Trade Information System (Etis).
It clearly identifies the Democratic Republic of Congo, Cameroon and Nigeria as the main sources of illegal ivory.
Raw ivory and trinkets made from it on sale in an Angolan market
"With myriad conflicts, central Africa is currently haemorrhaging ivory," observed Tom Milliken, director of Traffic's Africa programme.
"These three countries are major conduits for trafficking illegal ivory from the region to international markets, particularly in Asia."
The number of seizures fell between 1990 and 1995, but there has been a rising trend since then.
The number of large hauls - above one tonne - has also risen, which Dr Lieberman believes "demonstrates greater sophistication, organisation and finance".
China is identified as the single biggest market, though Traffic says enforcement has improved markedly in the last five years.
On the African side, the conservation group singles out Ethiopia for praise as a country which has effectively implemented an action plan drawn up by CITES four years ago, clamping down on its domestic ivory market.