Island medics attempted CPR before a doctor was flown in from neighbouring Moskito Island.
Sihle was then taken by boat to Peebles Hospital on Tortola, where he was pronounced dead from a head injury.
Police in the British Virgin Islands have launched a full investigation into the crash. A source told the Sun staff on Necker Island are working closely with local authorities to establish what happened.
Another insider alleged there had been “a culture of excess” at the luxury resort.
They said: “They’ve had very many close shaves and near misses over the years… it was only a matter of time, but it should never have happened.”
Sihle was described as a rising star in the culinary world.
The father-of-two had worked in high-end restaurants across the Middle East, including in Doha and Kuwait, before securing a position on Branson’s £95,000 ($218,024) a night private island.
Days before his death, Sihle shared images on social media of himself enjoying the beaches and jet skis at Necker Island, captioning one photograph: “Caribbean life”.