Having returned to the UK, Mr Lynch was preparing to campaign against what he viewed as Britain’s one-sided extradition treaty with the US.

In 2023, he had been escorted from his country home in handcuffs to a waiting plane and spirited across the Atlantic after then-home secretary Priti Patel signed off on his extradition. This was despite the UK’s Serious Fraud Office dropping a case against him years earlier.

“The system can sweep individuals away,” he said in a recent interview.

Over the weekend, Mr Lynch was aboard his personal yacht off the coast of Sicily. The boat, Bayesian, was named for the branch of statistics which was the subject of Mr Lynch’s Cambridge PhD.

Built in 2008, the 56-metre, 473-tonne superyacht is reported to have had capacity for 12 guests and 10 crew members with a top speed of 12 knots. Its listed owner is Ms Bacares, Mr Lynch’s wife.

On board with the couple were Charlotte Golunski, a partner at Invoke Capital, and her husband, James Emslie. Others on the vessel are reported to include business associates and legal advisers to Mr Lynch as well as the ship’s crew.

Ms Golunski, who was rescued from the vessel with her husband and baby daughter, told Italy’s Corriere Della Sera newspaper they were “all guests of our boss” who she described as an “extraordinary person”.