Back in August WhatsApp announced that it would start sharing its users' information, such as phone numbers, with its parent company. The app provided users with a notification, and an opportunity to opt out.

Now the information commissioner Elizabeth Denham says she has concerns that the consumers “weren’t being properly protected” as information is shared between the two companies. “I don’t think users have been given enough information about what Facebook plans to do with their information, and I don’t think WhatsApp has got valid consent from users to share the information,” she wrote.

The Information Commissioner’s Office has now asked Facebook and WhatsApp to be more transparent to their customers how their data would be used, and give them ongoing control over that information.

Earlier the use of WhatsApp users data was deemed illegal in Germany, and Facebook agreed to stop storing the data of German users of WhatsApp.