I’ve been following a similar thread on a U.S. forum, below is a post from a British poster;
As already explained Prince Andrew won't be going anywhere.
In 1978, a US court ruled that Prince Charles was immune from US civil proceedings as the son of a ruling monarch and the heir apparent, and the same will apply to Prince Andrew.
In 2016, in response to allegations of trafficking for sexual exploitation made by Ms Giuffre’s lawyers and an unconnected third party, the Metropolitan Police confirmed that, following a review of the “available evidence”, they would not proceed to a full investigation. This decision was recently reviewed and upheld.
The US also has to tread lightly due to damaging diplomatic consequences. As such, the FBI, for legal and/or political reasons, would most likely hand any evidence to the British authorities for a domestic prosecution. The CPS would then have jurisdiction to prosecute the Prince in relation to the alleged incident that occurred in the UK and, as well as any alleged incidents that occurred overseas.
However given the lack of evidence other than accusations, it is unlikely that enough hard evidence could be produced to warrant any action whatsoever, and a Civil Action would also be unlikely to succeed.