The watchdog is scrutinizing a number of food products, especially those that may serve as substitutes for price-capped products.
Government-mandated price caps now apply to granulated sugar, all-purpose flour, sunflower oil, pork leg, chicken breast and back, UHT cow's milk with 2.8% fat content, potatoes, and fresh eggs.
The probe will extend to the practices of the biggest supermarket chains. Individual complaints and market indicators will also be weighed.
GVH noted that it started consultations with market players in November to learn about trends on markets most affected by inflation and to inform businesses about compliance with competition regulations. It is also monitoring the situation abroad and studying the practices of other competition authorities in European Union member states.