Authorities in Germany said on Monday a probe had been launched into farms suspected of selling eggs as "organic" but not adhering to the conditions required for the label.
Prosecutors in the northwestern state of Lower Saxony are "investigating establishments that are suspected to have fraudulently sold organic and free-range eggs," a consumer affairs ministry spokesman told reporters.
The investigation, carried out by prosecutors in the Lower Saxony city of Oldenburg, began in 2011 and should be completed soon, the spokesman, Holger Eichele, told a regular government news conference.
Some 150 farms in the state and 50 elsewhere in Germany are under suspicion of not giving their chickens sufficient space to be able to claim they are selling "organic" produce, newsweekly Spiegel reported.
"If these accusations are confirmed, then we are talking about fraud on a grand scale," said Eichele.
"Deceiving the consumer but also the large number of egg farms in Germany which work and farm honestly and sell honest products," added the spokesman.
Speaking in Brussels ahead of an EU agriculture ministers meeting, German Consumer Affairs Minister Ilse Aigner said that, if found guilty, the culprits must face "the full force of the law."
"Consumers must be able to rely on the fact that what is written (on the produce) is also in there. Therefore it is important that this is checked," said Aigner.
According to federal statistics office Destatis, free-range and organic egg farming is on the increase in Germany. "Bio" food, as it is known here, is very popular.
In 2012, the number of chickens kept as free-range increased by 8.9 percent and as organic -- out in the open -- by 8.7 percent. The number of chickens kept in battery farms however declined by 4.2 percent.
The alleged scandal comes as Germany, like much of Europe, reels from revelations that undeclared horsemeat has found its way into a variety of products sold as "beef."