The 25-year-old boxer recently won gold at the Paris Olympics - but she subsequently launched legal action against the 'Harry Potter' author, Elon Musk and other public figures over comments they made about her gender, based on misinformation that surfaced online.
Nabil Boudi, Khelif's attorney, told Variety: "JK Rowling and Elon Musk are named in the lawsuit, among others."
The attorney also confirmed that former US President Donald Trump is part of the investigation.
Boudi explained: "Trump tweeted, so whether or not he is named in our lawsuit, he will inevitably be looked into as part of the prosecution."
Khelif - who was born female and identifies as a woman - has alleged "acts of aggravated cyber harassment".
The complaint has actually been filed against the social media platform X, which under French law, means that it was filed against unknown persons.
As a result, the prosecution has "all the latitude to be able to investigate against all people".
Boudi added: "What we're asking is that the prosecution investigates not only these people but whoever it feels necessary. If the case goes to court, they will stand trial."
Khelif won a gold medal in Paris over the weekend, and she subsequently admitted that "attacks" over her gender eligibility gave her victory a "special taste".
The boxer - who was banned from the World Championships in 2023 - claimed that she's been a victim of "bullying".
After winning gold in Paris, Khelif said: "I am fully qualified to take part in this competition. I am a woman like any other woman.
"I was born a woman. I have lived as a woman. I competed as a woman - there is no doubt about that."