The Metropolitan Police interviewed Giuffre in 2015 and 2016 but decided against launching a criminal investigation, a position it maintained after subsequent reviews in 2019, 2021 and 2022.
A spokesperson said the force had sought guidance from prosecutors and worked alongside US authorities.
They said: “Following this legal advice, it was clear that any investigation into human trafficking would be largely focused on activities outside the UK and perpetrators based overseas and therefore international authorities were best placed to progress these allegations.”
The spokesperson added: “A decision was then made in November 2016 not to proceed to a full criminal investigation.”
Giuffre had alleged she was trafficked to London in 2001 for sex with the now ex-Prince Andrew, 66, at the home of Ghislaine Maxwell, who was later convicted in the US for her role in Epstein’s crimes.
Andrew has denied the allegations and reached an out-of-court settlement with Giuffre in 2022 without admitting liability.
A Metropolitan Police spokesperson said the force is now “fully engaged” in a National Police Chiefs’ Council group established after the release of the new tranche of Epstein files, adding an assessment into whether London airports were used as transit points in trafficking activity remains ongoing.