Facebook Messenger users will be able to swap between Facebook and SMS contacts

Facebook is believed to be testing three new versions of its popular Facebook Messenger service on Android.

Alongside a new Material Design refresh, a number of new features are believed to be in testing ahead of an international roll-out.

Facebook is expected to include SMS support within its Android app. The standalone Messenger app had the ability to send and receive text messages back in 2013, but was later dropped.

Sources who have used the new beta app say text messages sent or received within the Facebook Messenger app appear in purple speech bubbles to differentiate themselves from those sent via Facebook.