Chris Brown has announced his new single will feature never-before-heard vocals from Aaliyah.

The 24-year-old rapper is set to release his track 'They Don't Know' - taken from his upcoming album 'X' - and has promised fans a ''special'' treat by including the late R&B star's voice, which will be heard for the first time since her death in 2001.

Speaking at the BET Awards 2013 press conference on Tuesday (14.05.13), where he was nominated for Best Male R&B/Pop Artist, Chris said: ''I got something special for my fans. It's called 'They Don't Know'. This song features Aaliyah. And never-before-heard vocals. All new stuff that's never been heard before.''

The 'Forever' hitmaker shot the video for the song in the Los Angeles ''hood'' last weekend (11.05.13) and hopes his chosen location will unite people from various backgrounds.

He added: ''I shot it in the 'hood. I went to 60th Street and Cedar Block.

''[I'm] bringing both worlds together and trying to uplift the poverty side of the community and show them where I'm from. I'm from Virginia, but everybody comes from a broken home or being broke - I remember when I was.''

Aaliyah is just one of many artists to feature on his unreleased album, which is out in July.

Other big names to lend their vocals include Nicki Minaj and Kendrick Lamar, in addition to production by Pharrell Williams, Timbaland, Polow Da Don, Danja and Drumma Boy.

Chris' use of Aaliyah's vocals comes after his rival Drake - who briefly dated his on/off girlfriend Rihanna - sampled her voice in his track 'Enough Said', which many listeners accused of being a vehicle to diss his foe.