Suppliers say the world's biggest wheat buyer has begun scrutinising cargoes more closely, reviving fears that tight import requirements could re-emerge following last year's row over ergot, a common grain fungus Egypt temporarily banned.

"The lab results came out today. We can confirm that there are poppy seeds that are harmful, or otherwise it wouldn't have been a problem for us," Agriculture Ministry spokesman Hamid Abdel Dayem said.

"The case will most probably now be transferred to the prosecutor," he said.

The wheat supplier, Transgrain France, the seller of France's only cargo to Egyptian state-buyer GASC this season, has insisted that any poppy seeds in the wheat would be a non-toxic variety, called papaver rhoeas.

The potential rejection of the cargo has caused dismay in France, where traders fear confusion over types of poppy seed will spark a costly dispute in a vital export market, two years after the rejection of a French cargo with trace levels of ergot sparked a year-long row and mass boycotts of Egyptian tenders.

If referred to the public prosecutor, the French wheat would join a 63,000 tonne Romanian wheat cargo which was rejected last month by the agriculture quarantine service and is still under review for potential re-export.

Suppliers pay about $10,000-$15,000 per day to keep their cargoes at the port and they are concerned their costs will mount if another import row develops.

"There is serious worry that another new problem like ergot might emerge. Representatives of many suppliers are requesting an official meeting with the Ministry of Trade to discuss the matter," said one European trader.

Traders say the tougher scrutiny by the quarantine service could be an attempt by inspectors to win back privileges lost under a new food inspection system implemented this year which halted the practice of sending them abroad to approve cargoes.

A group of inspectors successfully challenged the new system in court on concerns it was permitting harmful contaminants into the country but that verdict has yet to be implemented and is being appealed.

Traders said the prospect of cargo rejections could again make it tough for Egypt to attract suppliers to its tenders.

"It's getting very dangerous to do business with GASC ... I don't know what's going to happen" said one Cairo-based trader.