Britney Spears will duet with ex-boyfriend Justin Timberlake on her upcoming album, according to a new report.

The comeback-bound singer has been putting in long hours at the studio working on tracks for a follow-up to her 2007 release Blackout.

And, according to OK!, the Sexy Back star will be lending his voice to her latest musical offering.

"[Britney] is spending her summer in the recording studio, working on a brand new album," her record label has confirmed.

"She's working with a team of top-notch producers and songwriters and we're very excited about what she's accomplished so far."

Britney and Justin split in 2002 after four years together.

It was reported earlier this week that Britney hits out at her ex on one of her new songs.

On Already Bad she allegedly sings, “I know you thought you were the first/ But I had already quenched my thirst/ I was already bad” - apparently shooting down (her own) suggestions that she was a virgin before hooking up with Justin.