Singer Justin Bieber posted a photograph of a woman's derriere in a tight skirt on photo-sharing website Instagram and it is reportedly of his on-and-off girlfriend Selena Gomez.

In the well-framed image posted Thursday, the brunette is seen standing before a bed of red flowers, reports dailymail.co.uk.

The female is dressed in a form-fitting body con skirt, which hugs her buttocks and has long wavy tresses flowing around her shoulders.

Bieber and Gomez first started dating in 2010. They grabbed headlines recently after they reunited and were snapped together on various dates.