Zuckerberg told Brazilians to use Facebook Messenger while WhatsApp is blocked / GABRIEL BOUYS/AFP/Getty Images

The information will be shared to “improve [your] Facebook experience”, according to leaked screenshots from a developer

WhatsApp is to start sharing data with its owner, Facebook, according to leaked screenshots.

An update to the site looks set to introduce a new data-sharing tool that will see the two companies share user information with one another.

Facebook bought WhatsApp for $19 billion in 2014. It came with promises that the new owner wouldn’t interfere with WhatsApp data, which would remain safe.

A new version of WhatsApp appears to include the option to share user data with its owner to “improve [your] Facebook experiences”. But the sharing setting is turned off by default, according to Mr Santos.

It’s not clear what information will be shared with Facebook. And the site does appear to be asking people to through .

It’s likely that the two sites will share their contact lists and other details.

The new version of WhatsApp also brings a new end-to-end encryption indicator, which allows users to tell whether secure technology is being used in the chats. If that is turned on then nobody should be able to see what messages are being exchanged between users, which will be shielded even from WhatsApp.

WhatsApp dropped its subscription charge last week. That brings it more in line with Facebook Messenger, which makes its money from allowing companies to get in touch with users, as well as using information for advertising.