Gossip Girl star Michelle Trachtenberg has died aged 39

American actress Michelle Trachtenberg - best known for her roles in both Gossip Girl and Buffy The Vampire Slayer - has reportedly died.

According to a report published by ABC News, the 39-year-old was found dead on Wednesday 26 February in a New York City apartment near Columbus Circle, as per a police source.

Reports have also said her death is not being investigated as suspicious, and she is believed to have died of natural causes.

Trachtenberg reportedly underwent a liver transplant recently, as per ABC News.

They added that an autopsy will soon be conducted by the medical examiner's office to determine the cause of death.

LADbible Group has contacted NYPD and Michelle Trachtenberg's representatives for comment.

The actress' death is not being treated as suspicious (Gregg DeGuire/WireImage)

New York-born Trachtenberg made her acting debut as a child star, bagging roles in Nickelodeon projects at a young age - including The Adventure of Pete & Pete, and the kids' flick Harriet the Spy.

Her first serious role came in 1991 in an episode of Law & Order.

Between 2000-2003, she played fan-favourite formidable assassin Dawn Summers in Buffy The Vampire Slayer.

The role earned the star a Teen Choice Award nomination for choice TV sidekick

In 2005, Trachtenberg landed the lead role of Casey Carlyle in teen sports comedy-drama Ice Princess.

Her most successful roles came in the years that followed, however.

In 2008, she was cast as calculating high-schooler Georgina Sparks in teen hit Gossip Girl - alongside the likes of Blake Lively, Leighton Meester and Penn Badgley.

She also revived the much-loved role in the latest HBO Max reboot of the successful series.

Michelle kicked off her career as a child star (Steve Granitz / Contributor)

Following the news, tributes have been pouring in online from fans around the world.

"rip michelle trachtenberg," one wrote on X (formerly Twitter).

"i started ice skating because of the ice princess movie and her character was a huge inspiration for me :("

Another added: "michelle trachtenberg thankyou for giving us one of the most iconic female characters of all times. gossip girl would've been nothing without you."

A third gushed: "her style, her attitude made such an impression on me… she will be so missed"

"im so heartbroken, Rest In Peace Michelle Trachtenberg, you will never be forgotten," another continued.

"rip michelle trachtenberg you will always be a legend my icon," wrote a fifth fan.

Ed Westwick, best known for playing Chuck Bass on Gossip Girl alongside Trachtenberg, has now taken to Instagram to pay tribute to the star.

Writing on his story, the British actor said: "So sad to hear of the passing of @michelletrachtenberg sending prayers," accompanied with a prayer emoji and a white heart.