Washington, Aug 14 (ANI): Madonna has threatened Justin Timberlake with bodily harm if he reveals the details of their recent collaboration.

The 'Sexy Back' singer has been working with Madonna on her new album, and the two recorded a duet in London earlier this year.

However, Timberlake revealed that Madge has warned him not to talk about the song, or the album.

"I don't want to tell you the name of the song because she'll either kill me or have me kill you," Contactmusic quoted him, as saying.

The album has already been described as 'hot' by record producer Timbaland, who insisted that the singer performed marvellously on it.

In the meantime, reports have been circulating that the Material Girl is planning to celebrate her 50th birthday with a gig at New York's Central Park.

Madge is all set to tour the US next year to promote her next album, and once there, she is also thinking about bringing in her milestone birthday on August 16. (ANI)