Beyonce Knowles is teaming up with Lady GaGa for her upcoming single 'Video Phone'.

The two singers were spotted shooting a video for the song in a New York studio last week and all those involved were sworn to secrecy, reports contactmusic.com.

A source told Life&Style magazine that "Everything on the set was being kept very hush-hush, and security was extremely tight."

"In the video, Beyonce wears a feathered dress. And of course Lady GaGa wears something wild. The fashion is sick and insane," the source added.