This post deals with sexual harassment and might be triggering for some readers.
Sharing a lengthy statement to Twitter, Carpenter (who appeared in both Buffy and the spinoff Angel) explained how Whedon created a "toxic work environment" for both the cast and crew.
"Joss Whedon abused his power on numerous occasions while working on the sets of Buffy the Vampire Slayer and Angel," she wrote.
"While he found his misconduct amusing, it only served to intensify my performance anxiety, disempower me, and alienate me from my peers. The disturbing incidents triggered a chronic physical condition from which I still suffer. It is with a beating, heavy heart that I say I coped in isolation and, at times, destructively."
Carpenter also detailed moments where he abused her specifically. In her statement, she accused Whedon of threatening to fire her, pitting people against each other and calling her "fat" when she was four months pregnant.
She even explained that during a meeting, he asked whether she was "going to keep" the baby.
"In a closed-door meeting, he asked me if I was 'going to keep it' and manipulatively weaponised my womanhood and faith against me," she claimed.
"He proceeded to attack my character, mock my religious beliefs, accuse me of sabotaging the show, and then unceremoniously fired me the following season once I gave birth."
After Carpenter shared her statement, she was inundated with words of support.
"Buffy was a toxic environment, and it starts at the top. [Carpenter] is speaking truth and I support her 100 per cent," her former co-star, Amber Benson, wrote.
"There was a lot of damage done during that time and many of us are still processing it 20 plus years later."
While these allegations come as a shock to fans of the iconic '90s show, they aren't the first allegations against powerful people working on popular shows. Specifically, popular teen shows.