Japan has imported thousands of tons of bluefin tuna caught by Turkey in the Eastern Atlantic in violation of international agreements, according to the World Wide Fund for Nature.

The International Commission for the Conservation of Atlantic Tuna is expected to demand that Turkey observe international rules when it meets in Spain beginning Monday, sources said.

Japan is also likely to face criticism over its imports of illegally caught bluefin tuna.

The ICCAT does not allocate a national quota for bluefin tuna to Turkey but allows it, together with other countries, to catch a total of 1,146 tons a year in the Eastern Atlantic.

But the WWF, which analyzed trade data from ICCAT member countries, found that Turkey alone caught 3,300 tons of bluefin tuna in the Eastern Atlantic in 2003 and exported 1,457 tons to Japan.

The amount of Turkey's catch in 2004 is unknown, but it is known to have exported more than 3,900 tons to Japan that year.

Libya, which has been criticized for not reporting its fish catch data to the ICCAT, exported more than 1,000 tons of bluefin tuna to Japan in both 2003 and 2004.

The ICCAT does not regulate bluefin tuna trade among member countries, but the WWF has asked Japan to instruct importers not to buy bluefin tuna from Turkey and Libya.

The international environmental conservation organization, which raises funds to protect endangered species, has also asked the ICCAT to persuade member countries to impose sanctions on Turkey and Libya.

"We are aware of the issues about Turkey and other exporters," a Fisheries Agency official said. "We want them to observe international rules and provide credible data."

Japan is one of the founding members of the 41-member ICCAT, which was established in 1969. The ICCAT allows Japan to catch about 2,950 tons of bluefin tuna a year.