An Italian competition organization has given Apple, Google, Amazon and Gameloft twenty days to submit a defence to its investigation into in-app purchases or face a fine of up to €5M ($6.9M), reports ZDNet.

The companies now have 20 days to comply with the requests for information that came with the letter, and to respond with their defences to the allegations. If the alleged violations proved to be true, the three internet giants and the European game developer could each face a fine up to €5m — although the Italian watchdog told ZDNet that the punishment would be proportional to each company’s size.

The complaint is based on two concerns. First, whether consumers are clear about the likely total cost of the app at the time they download it. Second, whether sufficient information is provided about how to prevent or limit in-app purchases, especially in games played by children.

Apple settled a similar complaint with the FTC in January, after last year offering refunds to parents whose children had made in-app purchases. At that time, Tim Cook pointed to the safeguards in place, which include the ability to disable in-app purchases with a single switch, and requiring a password for any purchases made more than 15 minutes after downloading the app.

iOS also now alerts customers that further purchases can be made within 15 minutes without re-entering their iTunes password, and all iTunes apps that offer in-app purchases are labelled as such in the App Store.