FACEBOOK is gearing up to allow users to unsend private messages in its Messenger app.

A prototype of this feature was spotted by Jane Wong and she shared screenshots on Twitter explaining how it can be done.

She said: “Facebook Messenger is finally working on "Unsend Message" in the app for everyone!”

The screenshots show how a message a message is selected and how the user can either select an option to “unsend” or “delete” it.

However, users will be limited with how many times they can do this.

Jane added: “Facebook Messenger users will only be allowed to unsend their messages after a certain amount of times.”

It appears this feature has not fully rolled out for all Messenger users.

When The Sun Online tested to see if the feature was available only the “delete message” option existed.

It comes six months after Facebook admitted that it was purging messages sent by Mark Zuckerberg – a feature unavailable to normal users, according to a TechCrunch report.

In a statement given to The Sun about the Zuck purge, a Facebook spokesperson said: "After Sony Pictures' emails were hacked in 2014 we made a number of changes to protect our executives' communications.

"These included limiting the retention period for Mark's messages in Messenger.

"We did so in full compliance with our legal obligations to preserve messages."

But the revelation spark fury among users, who questioned why Facebook's billionaire boss was allowed to delete messages, but normal users weren't.

The current Facebook Messenger app lets you delete messages – but it'll still appear to the recipient(s).

There's no way right now to delete messages sent to other users so that they can't see them any more.

That's in contrast to Facebook-owned messenger WhatsApp, which lets you unsend messages up to an hour after being sent.

And Facebook's Instagram photo-sharing app lets you unsend Direct Messages whenever you want – even years after you originally sent the message.

According to the TechCrunch report, Facebook still hasn't finalised exactly how the unsend feature will work.

One possible option being explored is an expiration timer that users could set on messages when they send them.

It's believed that this is how Mark Zuckerberg's own message retractions work.

When the timer runs out, the message would disappear from all recipients' inboxes.

The fact that Mark Zuckerberg's unsend tech already exists means it should be very easy to roll out to users.