AceShowbiz -

Britney Spears' brand new song is called "Dirty Girl", so revealed music producer Russ Castella. "Working on the new britney track...but shhhh it's supposed to be a secret," he wrote on his Twitter. "The new britney track is called 'Dirty Girl' and its gonna be realllllyyyyy dirty."

Russ Castella is well known for his work on remixing hit singles from such artists as Lil Wayne, Ciara and Keri Hilson. Up to date, it is unclear whether or not the new song he works for Britney will be included in her upcoming greatest hits album.

Beside working with Russ Castella, Britney Spears recently tweeted about hitting studio with acclaimed producer Max Martin. Moreover, recent rumor suggested she will drop the hits compilation tentatively titled "The Singles Collection" in late October.

In the meantime, Britney has announced a number of tour dates in Canada and North America. She has billed Ciara and Kristinia DeBarge as supporting acts, and will start the gig at Copps Coliseum in Hamilton, Ontario on August 20. Then, she will finish it off at Mandalay Bay Events Center in Las Vegas, Nevada on September 27.

In an interview with Entertainment Tonight, Britney said, "We have a song called 'Mannequin' that we're adding to the show, which I'm really, really excited about, so it should be interesting. We have to update [the show] or it gets really boring." More detailed info about her forthcoming shows can be seen on her official website.