CAIRO- Egypt, the world's largest wheat importer, has rejected a shipment of Romanian wheat over a "quality issue," an official with knowledge of the matter told Reuters on Tuesday.

"We have given a final rejection, it is now up to the seller and Egypt's General Authority for Supply Commodities (GASC) to decide how they will deal with their contract," the official said.

The official said the cargo was still at Egypt's Dekheila port.

A trade source with knowledge of the matter said the shipment was rejected due to an issue with its falling number, the internationally standardised and most popular method for determining sprout damage and so the milling quality of wheat.

"There is no way to fix a falling number issue; it can't be sieved or fumigated for example, that's why when you fail that test, it's done," the trade source said, adding that the shipment was tested twice and failed.

The seller has the right to ask for a third test but the official said a decision on the shipment had already been made.

A European trader closely involved in GASC tenders said he had not heard of any widespread problems with Romanian wheat.

GASC was not immediately available for comment.

Egypt rattled the market in 2016 when it reinstated a ban on even trace levels of ergot, a common grain fungus that can lead to hallucinations but is considered harmless at minor levels.

(Reporting by Maha El Dahan in Dubai, Nadine Awadalla in Cairo; Additional reporting by Michael Hogan in Hamburg; Editing by Jane Merriman and David Evans) ((;))