London - British tech tycoon Mike Lynch, who capsized off the coast of Sicily in August last year, was knocked down by "extreme wind" and could not recover, British investigators said Thursday.

Lynch, 59, and his 18-year-old daughter Hannah sank on August 19 last year in the Bayesian at 56 meters (184 feet). The boat trip was a celebration of Lynch’s acquittal in the U.S. fraud case in June.

In an interim report on the disaster, the British Marine Accident Investigation Department said the ship had a lighter demeanor to the wind than the tilted wind. The report said the report is based on “limited evidence of verification” as Italian authorities’ criminal investigations limit their opportunities for wreckage and other evidence.

The agency is investigating the disaster because the Bayesians are registered in the UK, saying the "voids" are "unknown to the owner or crew" because they are not included in the stable information book on board.

The report noted that the Bayes were sailed to the site that had sunk the day before to avoid predicting thunderstorms. It said the disaster occurred at 4:06 local time, when winds exceeded 70 knots (81 mph), "hardly" hit the ship to a 90-degree angle below 15 seconds.

It said that at the time of the incident, the ship was in a "car condition" with its sail lowered, while the center plate used to stabilize it was in a "high" position.

"Your wind pushes the ship on top and then makes the ship's stability try to push the ship to the right again," said MAIB investigator Simon Graves. "Our research found that they suggest that Bayesians may be vulnerable to strong winds and that these winds are obvious at the time of the accident."

The UK's inquiry program is studying the deaths of Lynch and his daughter, as well as Jonathan Bloomer, 70, the chairman of Morgan Stanley International Bank, and his wife Judy Bloomer, 71, are both British nationals.

Others who died in the sinking were American lawyer Chris Morvillo and his wife Neda Morvillo and Canadian-Antiguan country Recaldo Thomas, who served as chefs on board.

15 people, including Lynch's wife, Angela Bacares, were rescued.

A project that transfers Bayesians to an upright position and lifts them to the surface has been since the divers died in underwater work since May 9. Recovery will resume from Thursday.

Graves said the final report will include more details such as the "escape route."

"Once we can use the vessel, we can tell a more comprehensive picture of the events and sequence of events on board," he said.

The date on which the final report will be released has not been determined.