It was one of WhatsApp's most highly-anticipated features, but it seems that the 'Delete for Everyone' tool isn't quite as reliable as you might think.
A new report claims that WhatsApp messages that are deleted are actually still on the device, and can easily be accessed through Settings.
The workaround appears to be available for Android 7.0 users, although it is unclear if a similar hack is available on iOS.
Last month, WhatsApp introduced a 'delete for everyone' feature, allowing users to unsend an embarrassing message within seven minutes of sending it.
But
Android Jefe, a Spanish Android blog, noticed a workaround that allows Android users to view unsent messages.
Santiago S, the author of the blog, wrote: 'We have discovered a way to recover or see messages deleted by the other person in a WhatsApp chat.
'What we found is that the messages are stored in the notification register of the Android system.
'So, it's just a matter of entering that record to see the messages that the other person deleted.'
Whenever a notification comes in to an Android devices, it is stored in the notification log – whether or not it is subsequently deleted by the sender.
While the bulk of the data in the log is technical information, the first 100 characters of the notification message are also recorded.
So while users may not be able to see the message within WhatsApp after it is deleted, they can still see it in the notification log – which can be accessed in two ways.
Firstly, users can create a home screen Settings widget, in which a 'Notification Registration' option will appear, according to Android Jefe.
Alternatively users can download a notification history app, which displays a list of all your recent notifications.
The first 100 characters of the message will appear in the line starting with 'android.text.'
Android Jefe highlights some important limitations to retrieving messages.
Users will only be able to view the first 100 characters of deleted messages, and the notification log will clear every few hours, or any time the device is restarted.
Android Jefe also claims that only messages that have already been seen or interacted with can be retrieved.
However, during Mail Online's testing, the recipient had to have read the message before it was deleted for it to appear in the Notification Log.
And the technique will only work on Android 7 - it is unclear if it will work on higher versions.
The discovery raises important security issues with WhatsApp.
One of the main reasons people use WhatsApp over text messaging is that it uses end-to-end encryption, that is seen as a secure option.
But while message transmission may be safe, the discovery suggests that notification storage may be an issue.
A spokesperson for WhatsApp told
Tech Republic
that the message deletion option doesn't delete notifications.
MailOnline has contacted WhatsApp for further comment.