Mel B poses nude in a swimming pool

Singer Mel B arrives at the iHeartRadio Music Awards in Los Angeles, California May 1, 2014. (Reuters)

Mel B has posed totally naked in a swimming pool with her best friend for her latest social media snap.

The Spice Girl took to Instagram this morning to share a couple of pictures with her BFF Gary Madatyan, with the pals both stripping off to have fun in the water.

In one picture, Gary grins at the camera as Mel, 43, wraps her arms around his neck and arches her back and lifts herself slightly out of the water.

The star shows off her trim waist and pert bottom as she emerges from the water, captioning the shot: "Back to basics naked but never ever afraid finally,with my Bestie @gary_90210 #blessd #trust #nojudgement #brutallyhonest #nodrama."

In a second shot, Mel shows off her back tattoo and sits side on to the camera while Gary looks directly down the lens and puts one arm in the air.

She wrote alongside it: "And then there where 2 #truefriendshipneverends #brutallyhonest #truth."

The singer referred to her upcoming autobiography's title in the post, with her tell-all book - "Brutally Honest" - being released in November.

However Mel has been blocked from discussing details about ex Eddie Murphy.

The Spice Girls star will face a hefty payout if she details their turbulent relationship, which resulted in daughter Angel, 11.

Despite the twice-married star promising the book would tell all about the men in her life, the 2007 gagging clause is causing a headache with the writing process.

This article originally appeared in The Sun.