French authorities have launched a preliminary probe to uncover whether any sexual assault offences linked to the case against American financier Jeffrey Epstein were committed on the country's soil or on French nationals.

The Paris Prosecutor's Office announced the investigation on Friday, saying it was instigated after "checks, cross-referencing and exchanges with the competent authorities in the US."

The charges under investigation include rape and sexual assault on minors over the age of 15, rape and sexual assault on minors under the age of 15, criminal conspiracy to commit crimes and association of criminals with a view to committing offences punishable by at least five years of imprisonment, the prosecutor's statement added.

Epstein was found dead in his New York prison cell on August 10 in an apparent suicide, later confirmed by an autopsy.

The 66-year-old billionaire and registered sex offender had been arrested a month earlier and charged with sex trafficking and conspiracy to commit sex trafficking.

The French NGO "Innocence en danger" called on the country's authorities to launch an investigation on July 12, citing Epstein's arrest upon his return "from a weeks-long trip in France."

"He owns a property in Paris, which he visits regularly," the NGO said in an open letter, adding: "it is legitimate to wonder if there are any minor victims" in the country.

In a second open letter, published on August 12 by the Obs news outlet, "Innocence en danger" affirmed that "several victims are French."

The case against Epstein has garnered interest worldwide due to the rich and famous people he was associated with including former US President Bill Clinton, current President Donald Trump and Britain's Prince Andrew.