A singer who took part in The Voice has denied allegations of rape made against her by a former friend on Twitter.

In a post uploaded to Twitter on Monday, Timothy Heller, 22, accused her former friend, Melanie Martinez, of sexually assaulting her. In the post, Heller alleged that Martinez pressured her for two nights to engage in sexual acts despite Heller repeatedly saying no “in every form I could think of.”

Heller then describes how Martinez convinced her to get high on marijuana before forcefully performing oral sex on her and penetrating her with a sex toy.

Martinez responded to the allegations in a tweet of her own, stating she is “horrified and saddened” by the claims.

Heller claims this assault, which happened over a two-night sleepover, occurred despite her constant refusals.

“I never said yes. I said no, repeatedly,” wrote Heller before continuing, “Just so there is no confusion, I was molested by my best friend.”

Heller then explained why she decided to come forward now, “The only reason I do this now is because I’m hoping because of recent events, people will believe me” and urged readers who may doubt the story to “imagine her role in this being a man.”

Concluding her post, Heller wrote, “Girls can rape girls. Best friends can rape best friends. Friendship does not equal consent. Silence doesn’t equal consent.”

Martinez used her tweet to imply that everything that happened between them was consensual.

She wrote: “I am horrified and saddened by the statements and story told tonight by Timothy Heller. What she and I shared was a close friendship for a period of time. We came into each other’s lives as we were both starting our careers as artists, and we tried to help each other. We both had pain in dealing with our individual demons and the new paths we were forging, but I truly felt we were trying to lift each other up. She never said no to what we chose to do together. And although we parted ways, I am sending her love and light always.”

However, both women have received tweets of support.

Heller’s post received comments such as, “I am so so sorry. You’re so strong for sharing. Sending positive vibes your way” and “I’m so sorry this happened to you. I am genuinely so disappointed in her, thank you for being brave enough to share this.”