Lady Gaga is working on a collaboration with Azealia Banks.

The Born This Way star and the 212 rapper have sparked speculation after they exchanged messages on Twitter for all their followers to see, hinting they are working together.

Azealia tweeted: "When Mother Monster calls...", and then added: "Sh** is about to get very f***ing real. [sic]"

Lady Gaga then revealed the pair had been speaking to one another when she tweeted Azealia saying: "Can you make 99 Problems my ring tone for when I call you, and then shout B**** Ain't One at me when you pick up? [sic]"

Azealia later joked: "Talking to Lady Gaga on tha twitta ... NBD," before adding: "HUGE DEAL. [sic]"

Lady Gaga has previously collaborated with artists including Beyonce on the hit Telephone, while rapper and singer Azealia has collaborated with Lana Del Rey and M.I.A and recently revealed on Twitter she is working with Kanye West.

It has also been rumoured Azealia could be signing up to join Lady Gaga as a support act on her ongoing Born This Way Ball world tour.