Cairo denied responsibility on Wednesday for an E. coli outbreak that killed 50 people, mainly in Germany, blamed by the European Union on fenugreek seeds imported from Egypt.
The Egyptian agriculture ministry said the suspected batch dated back to November 2009 and contained dried seeds, arguing the bacteria could not have survived for so long.
"Scientifically, the bacteria cannot remain on this dry surface from 2009 till June 2011," the ministry said.
"If the fenugreek sprouts are suspected of being contaminated by an E. coli strain, it could be down to different processes such as their re-packing or the water used for sprouting," the statement added.
The European Food Safety Agency (EFSA) on Tuesday singled out the 15-tonne batch imported to Germany and then distributed elsewhere as "the most likely common link between the two outbreaks" but added that subsequent imports could also be implicated.
As a result, the European Union slapped a temporary ban on all seeds and beans from Egypt.
"The report published today leads us to the withdrawing of some Egyptian seeds from the EU market and to a temporary ban on imports of all seeds and beans originating from that country," EU health commissioner John Dalli said.
The World Health Organisation has confirmed 4,050 infections related to the outbreak across 14 European countries, the United States and Canada, the majority of them in Germany.
According to the latest figures, 48 people have died in Germany, one in the United States and another in Sweden.
Seven people were infected with E. coli in France after eating vegetable sprouts at a leisure centre near Bordeaux.
The import ban, to be enforced until October 31, hits all Egyptian seeds, fruit and spores used for sowing -- including soya beans, dried leguminous vegetables and oil seeds.
The EFSA report said the contamination probably occurred before the seeds left the importer.
"The production or distribution process apparently allowed contamination with faecal material of human and/or animal origin.
"Where exactly this contamination occurred is still unknown," the EU said.
Russia also decided Wednesday to halt imports of some seeds from Egypt.
Russian consumer protection watchdog chief, Gennady Onishchenko, said the ban also applied to some soy products, mustard and certain other vegetable seeds.
"Until special (new) instructions, we are also introducing a ban on the import and sale in our country of certain types of Egyptian products," Interfax quoted Onishchenko as saying.
Russia last week resumed vegetable imports from four European Union countries after imposing a nearly month-long ban because of the deadly bacterial strain.
The Egyptian agriculture ministry stressed that all tests on produce have come back negative and that the E. coli strain has not been reported in Egypt.