An inspection at Kaufland conducted a few days ago found that the chain was selling cartons of mixed eggs, both labeled and unlabelled.

Novinite.com reports that some of the eggs in the cartons imported from Poland had red dots indicating that they were from hens kept in cramped cages.

The sale of eggs with red dots, which do not meet the EU minimum standards for the protection of laying hens, is forbidden in Bulgaria.

Asked to comment on the matter, Agriculture Minister Miroslav Naydenov said on Monday that the Polish farm obviously had some cages which were in line with EU requirements and some which were not.

He assured that the eggs were safe but were sold in breach of EU animal welfare standards and of fair competition rules because they were cheaper by around EUR 0.02.

"The batch of eggs sold at Kaufland, which attracted widespread media coverage on January 30, 2012, is accompanied by all the necessary documents. The paperwork confirms that the eggs meet EU welfare standards for laying hens," the hypermarket chain said in a statement Wednesday.

Kaufland Bulgaria insisted that they could provide a document issued by the Bulgarian Food Safety Agency certifying the compliance of the product with the standards at the point of reception at the main warehouse of the chain.

The retail chain suggested that the inspection had been launched on a tip-off by a contractor of theirs.

Kaufland Bulgaria assured that the unlabelled eggs had been pulled from store shelves and would be destroyed.

"We expect that control organs, the media and citizens will show understanding that egg-labeling is a technological process which involves technological process errors," the hypermarket network stated, protesting the deliberate attempt to tarnish its image.