Cassie could be expecting REUTERS/Lucas Jackson

Diddy's long-term girlfriend Cassie has sparked pregnancy rumours after she posted pictures of herself with a fuller face and a bulging belly on Instagram.

Eagle-eyed fans began to question whether she was expecting when she uploaded the black and white photo of herself sporting blonde highlights and hoop earrings.

But within minutes she took the photo offline and replaced it with a cropped version that excludes her tummy.

When fans revealed that they were unconvinced, she later uploaded a photo of herself in a bikini showing off a very flat stomach.

Cassie Ventura
Cassie dispels pregnancy talk with Instagram snaps instagram

The photo on the right is alleged to have been taken on a holiday last year as the singer is sporting a completely different hairstyle and has a visibly reduced bust.

The snap comes weeks after the 27-year-old songstress was seen leaving a fertility clinic with Diddy. If she is pregnant, it will be the first child for her and the sixth for the rap mogul.

This isn't the first time the couple have had to combat rumours about their relationship this year. In Feburary, Cassie took to Instagram to refute claims that she and Diddy were getting married.