Beyonce has fuelled rumours that she is pregnant after posting a picture of herself in the sand with an enlarged belly. Beyonce /Instagram

Speculation is mounting that Beyonce is pregnant with her second child.

The 33-year-old singer fuelled the rumours by posting a picture of herself on Instagram covered in sand, with her stomach shaped into a baby bump.

In the beach photo, the Flawless singer is seen wearing oversized round sunglasses with only her face exposed.

The image comes after Jay Z first hinted that his wife is pregnant, during the first of two Paris shows while on the European leg of their On The Run tour in September.

The rap star is reported to have changed some of his lyrics to the track Beach Is Better, to include the words "cause she pregnant with another one."

The music power couple, who have a three-year-old daughter Ivy Blue together, have been married since 2008 and have been vocal about wanting to expand their brood.

The family were recently on holiday in Southeast Asia, where they were spotted sightseeing at Cambodia's historic Buddhist temple Angkor Wat.

The Single Ladies singer was also seen on the trip wearing a loose-fitted leopard print blouse, seemingly covering up her burgeoning belly.

The images have prompted Beyonce's fans to turn to Twitter to express their excitement about the possibly impending pregnancy.

"IS BEYONCÉ TRYING TO TELL US SHE'S PREGNANT?????!?!?!?!?!?!?!?!!" wrote one Twitter user.

The couple's marriage was plagued by reports of infidelities, following the infamous lift attack in which the singer's sister Solange Knowles attacked Jay Z.