Mr. Sala’s family had commissioned a private search after the authorities ended their search of the Channel’s surface and small islands on Jan. 24. David Barker, the harbormaster of the island of Guernsey, a self-governing British dependency off the coast of France, said in a statement at the time, “The chances of survival at this stage are extremely remote.”
Mr. Sala, 28, a prolific goal scorer for Nantes in the French league, had recently been transferred to the Premier League club Cardiff City and was scheduled to practice with the Welsh team for the first time the next day.
The flight went through rough, wintry weather over the Channel, and Mr. Sala left a voice message for friends and relatives saying that he was afraid that the plane would break apart.
After the authorities ended their search, Romina Sala, Mr. Sala’s sister, pleaded with the authorities not to call it off.
“Please, please, please don’t stop the search,” Ms. Sala said at a news conference in Cardiff, fighting back tears.
She said she knew in her heart that Mr. Sala was still alive somewhere in the Channel.
A Facebook message to Mr. Sala’s sister seeking comment was not immediately answered on Sunday night.
People from all over the world — including soccer stars like Kylian Mbappé, a member of the French national team that won the World Cup last year — chipped in to help the family’s search.
Sport Cover, a Paris-based soccer agency, started a GoFundMe page on Jan. 25 that by Sunday evening had raised more than 371,000 euros, about $424,000.
Geo Ocean III departed Ostend, a coastal city in Belgium, on Sunday morning to begin a three-day underwater search, the A.A.I.B. tweeted. The search area was to cover about four square miles, according to the BBC.
On Sunday evening, after the wreckage was discovered in the English Channel, Mr. Mearns told Sky News: “This is about the best result we could’ve hoped for the families, but tonight they’ve heard devastating news.”