In April 2008, almost all regulations for food packaging were dropped, but now some companies are scamming consumers by charging the same price for slightly smaller amounts of food, VZVB spokesman Armin Valet told news agency DDP on Wednesday.

“Consumers will be hit with many more hidden price increases across a variety of goods,” he said.

Using mystery shoppers and other techniques, VZVB discovered that the product content reductions led to the equivalent of a 20 percent price increase for dish washing liquid and 10 percent for diapers.

Similar tricks were also discovered in the fruits and vegetables section of the supermarket. There agents found that there were only 400 grammes of bell peppers and tomatoes in same 500-gramme packages that had been used before the regulations changed. And a tube of Pringles potato chips now weighs just 170-grammes, when it used to weigh 200 grammes.

The agency also found some odd explanations for the practice among some of the tricksters. One major dog food manufacturer claimed that quantity reductions were motivated “entirely by the wishes and demands of the customer.” The claim was based on a survey that concluded customers prefer a size reduction to a price increase.

“Only by looking at the increase in the base price of the product can a consumer cotton on to the tricks used by the sellers, “ Valet told news agency AP. Unfortunately, in many supermarkets, this is often missing, illegible or only available for goods sold by weight. It doesn’t therefore act as an indicator for those sold by quantity of pieces.

A full list of offending products can be found on the VZVB website.