In the offending image, Beckham balances on one leg, hiking the other up and wrapping an arm around it as she leans into the lens.
Seemingly oblivious to the error in the image, the 41-year-old posted: "Loved working on this shoot for @voguechina May issue.
"Thank u [sic] @inezandvinoodh, @wendyrowe, @georgecortina and @shayashual x vb."
Fans were quick to highlight the error, with Taylor_morcom, writing: "The pic when she is holding her leg the thigh of her back leg is missing".
Others posted "Bad photoshop" and "Photoshop fail".
But friends of the star disputed the claims. @Estmanning wrote: "Stunning!! Someone said the thigh of her back leg is missing but it's just her shirt."
Similarly, @Josephinekent84, wrote: "Her leg has been 'cut out' she hasn't it's the shorts coming underneath and between her legs."
Since leaving pop group the Spice Girls, Beckham has turned her attention to fashion and has recently opened a boutique in Hong Kong, her first in Asia.
- nzherald.co.nz