Brown's unreleased duet with Rihanna lands online

The "Put it up" duet by singers Chris Brown and Rihanna has been leaked online.

The song was originally planned to be featured on Brown's 2014 album “X”, but was scrapped after he broke up again with Rihanna in 2013, reports aceshowbiz.com.

"Put it up" opens with a verse from Rihanna, who sings about falling in love with her man and encouraging him to love her back. Brown then emerges to croon about how she is his number one girl.

Rihanna later joins her former boyfriend as they sing provocative lines like: I'mma write my name with my tongue on your back baby/ Come on, just let me/ I know you're ready.”

"When I'm with you, don't be scared/ When I start to go down and I lick you/ Rubbin' and kissin' and lickin' on your body/ When I go down and oh I'm gon' miss you/ Gonna need your body right now.”

The duo have also sung "Birthday cake" and "Nobody's business" together after their split.