Reality TV star Kim Kardashian has slammed rumours that she had Photoshopped her pictures before posting them on Instagram after she gave birth to her baby.

She insists she has worked hard for her post-pregnancy figure.

The `Keeping Up with the Kardashians` star has blasted rumours she digitally altered a recent photograph of her and her friend Blac Cyna to make them appear thinner before posting it on photosharing site Instagram, reports contactmusic.com.

Addressing the allegations on Twitter Friday, the 32-year-old posted: "It sucks when people make up surgery or Photoshop lies when I am so disciplined and work so hard. Just trying to motivate others and show anyone struggling with weight they can totally achieve whatever they want if they are dedicated."

Kardashian recently revealed she has lost more than 50 pounds since giving birth to her daughter, North West, in Los Angeles in June.