Actor Ansel Elgort has denied an allegation in which a woman has accused him of sexually assaulting her in 2014 when she was 17-years-old.

The woman, who identified herself as 'Gabby', made the allegation online on Friday. She claimed that the alleged incident occurred after she had sent Elgort, who was 20 at the time, a direct message online and then was given his private Snapchat account details. She said she is now "ready to talk about it and finally heal".

In a statement posted to his Instagram account on Saturday evening, Elgort wrote: "I was distressed to see the social media posts about me in the last 24 hours. I cannot claim to understand Gabby's feelings but her description of events is simply not what happened. I have never and would never assault anyone."

"What is true is that in New York in 2014, when I was 20, Gabby and I had a brief, legal and entirely consensual relationship," Elgort continued.

"Unfortunately, I did not handle the breakup well. I stopped responding to her, which is an immature and cruel thing to do to someone. I know this belated apology does not absolve me of my unacceptable behavior when I disappeared."

He concluded: "As I look back at my attitude, I am disgusted and deeply ashamed of the way I acted. I am truly sorry. I know I must continue to reflect, learn, and work to grow in empathy." 

Elgort is best known for his performances in the films Baby Driver and The Fault in Our Stars.