Premier League footballer Emiliano Sala is missing after his flight from the French city of Nantes to Cardiff lost radar contact off the English Channel island Guernsey late on Monday.
Mr Sala had signed with Cardiff City over the weekend for a record $27 million signing and was making the trip to South Wales when his plane lost contact.
Rescue aircraft and boats scoured more than 1,000 square miles of sea for the single-engine Piper Malibu on Tuesday.
Guernsey police said a number of floating objects had been seen in the water but they were unable to confirm whether any were from the missing aircraft.
As night fell, search operations were suspended. Police said they will resume at sunrise on Wednesday.
Argentine newspaper Clarin published a voice message that Sala apparently sent to friends.
“We’re up in the plane and it seems it’s about to crash,” said the message, which Clarin said was verified by Sala’s father, Horacio Sala.
“If you have not heard anything from me in an hour and a half, I don’t know if they’re going to send someone to find me, because, you know, they’re not going to be able to,” the message said. “Dad. I’m really scared.”
Mr Sala's last social media post was of himself with his Nante teammates with the caption: "The last goodbye".
Forward Sala, 28, joined Premier League strugglers Cardiff from FC Nantes last week for a club record fee of about 17 million euros (£15 million). He had played in France since 2012.
"We expected Emiliano to arrive last night into Cardiff and today was due to be his first day with the team," club CEO Ken Choo said in a statement. "We continue to pray for positive news." Tuesday's training session was called off.
"The management and the whole club are staying hopeful and the whole FC Nantes family is praying for Emiliano Sala and the other passengers to be found safe and sound," Nantes said in a statement.
British authorities contacted airfields along the coast to check if the plane had made an unplanned landing, but there was no sign it had, Guernsey police said.
The plane had been cruising at 5,000 feet when the pilot requested to descend to a lower altitude on passing Guernsey. It lost radar contact at 2,300 feet, the police said.
John Fitzgerald, chief executive of Channel Islands Air Search, said: "If they are wearing the right dry suits or they got into a life raft, then the probability is not too bad.
"If they are in the water without any protection, the water is really too cold at the moment for any form of survival beyond an hour or so," Fitzgerald told Sky TV.
Sala's father Horacio told Argentine TV channel C5N: "I didn’t know anything because I’m away from home, I’m a truck driver. A friend who saw it on TV told me. I'm in despair."
Supporters gather to pay tribute to Argentinian soccer player Emiliano Sala, in Nantes, France, on Tuesday, Source: AP
Julio Muller, the mayor of Progreso, the small town in the farming province of Santa Fe where Sala grew up, told Clarin online: "The town is in shock. The only thing we were talking about was his transfer."
Daniel Rivero, the president of Sala's first club, San Martin de Progreso, told radio LT9 he was "hoping for some kind of a miracle."
Sala scored 12 goals for Nantes this season.
France's football federation postponed Nantes's French Cup last-32 game against Entente Sannois-Saint Gratien that was scheduled for Wednesday.
