Cara Delevingne
The model highlighted the obvious similarities between male and female breasts. Cara Delevingne / Instagram

Cara Delevingne has posted a provocative image on Instagram in support of a growing social media campaign for topless rights.

The photo, posted to the 21-year-old's 6 million followers, depicts a topless man and woman.

Drawing on the image Delevingne highlights the anatomical similarities between the male and female bodies but with a tape over the female nipple.

Under the man's photo is the word 'Free', while under the woman's picture is the word 'Censored'.

It is not known whether it is Cara in the photo.

The model also posted an image of a woman in a flesh coloured bikini top complete with nipple prints.

Delevingne followed the provocative images with an e-card on Instagram which read: "Just thought you should know every single Senate Republican just voted against equal pay for women. It's about time for equality #EQUALITY"

The 'Free the Nipple' campaign is an equality movement that uses social media to fight against censorship laws in the US, where it is illegal in 37 states for women to appear topless.

In February, the controversial celebrity was seen wearing a 'Free the Nipple' T-shirt, which featured a pair of breasts emblazoned across her own chest, during a high-profile visit to the home of the American Ambassador.

The campaign has gained the support of celebrities including Demi Moore and Bruce Willis's daughters Rumer and Scout Willis and singer Rihanna.

On Sunday (13 July), actress Caitlin Stasey spent the day braless and publicised it via social media in solidarity with the movement.