A recent investigation that found Instacart is charging some customers nearly 25% more for the same products from the same store got a lot of people’s attention, including the Federal Trade Commission. According to a report from Reuters, the agency has opened a probe into Instacart’s pricing practices.

Instacart, an online grocery delivery service, is being accused of charging shoppers different prices without their knowledge, with some items costing 20% more.

New research shows a country-wide experiment by Instacart has been charging shoppers different prices for the same product at the same store.