The former child star, who began her career in TV commercials at age three, was best known for Harriet the Spy, Buffy the Vampire Slayer and Gossip Girl.

Her mother discovered her body around 8am on Wednesday at One Columbus Place, a luxury high-rise in Manhattan’s Central Park South neighbourhood.

Actress Michelle Trachtenberg, best known for her role in the ‘Gossip Girl’ series, has died at the age of 39.

Actress Michelle Trachtenberg was found dead at her New York apartment on Wednesday morning. Picture: Instagram

The NYPD confirmed she was found “unconscious and unresponsive” and was pronounced dead at the scene by emergency responders.

The Gossip Girl favourite had recently undergone a liver transplant, and America’s ABC reported she may have suffered complications.

Trachtenberg was an active presence on social media, regularly sharing photos of herself, but in recent months, her followers had expressed growing concern about her appearance.

While she never publicly disclosed any health struggles, fans left comments speculating about her well-being, with some suggesting she looked “sick”.

“That is not Michelle,” one person commented on an Instagram post from February 13, while another wrote: “This looks like a completely different person.”

“There is something wrong and I am not a hater,” another fan posted on January 27, a comment that received over 800 likes.

“Damn, you look like you need help,” another said, while one asked bluntly, “Are you sick?!”

These remarks were nothing new for Trachtenberg, who had been fielding similar comments for over a year.

“Explain to me how I look sick,” she clapped back at one critic last year.

“Did you lose a calendar and not realise I’m not 14? I’m 38. How sad for you to leave such a comment.”

She also shared a selfie alongside a defiant message addressing the speculation over her looks.

“I’ve received several comments recently about my appearance. I have never had plastic surgery. I am happy and healthy. Check yourself, haters.”

Despite her insistence that she was fine, many fans condemned the criticism and defended the actress.

“Hi Michelle. I don’t know if you’ll ever read this, but I wanted to tell you that I’ve heard the criticism you’ve received, and honestly, you don’t deserve it,” one person wrote.

“These comments are awful. You have no idea what’s going on and if she’s asked for help or not. It could be something out of her control,” another said.

Since her death was confirmed, an outpouring of tributes has flooded in from fans and Hollywood colleagues, including her former Ice Princess co-star Kim Cattrall.

“This is heartbreaking. So talented, much too young. RIP Sweet Beauty. xo,” Cattrall posted on X.

A representative for the actress confirmed her passing in a statement to NBC on Wednesday evening.

“The family requests privacy for their loss,” they said.

“There are no further details at this time.”

Trachtenberg’s death is not being treated as suspicious, and a coroner will determine the exact cause.