Rescuers searched Wednesday for a missing plane carrying Cardiff City's record new signing Emiliano Sala, as it emerged the Argentine striker had sent relatives a desperate message shortly before the light aircraft disappeared over the Channel.

Floating objects have been found in the water, and police on the British island of Guernsey, which sits off the north coast of France, have warned the chances of the passengers surviving were "slim".

As the air search resumed, Argentine media reported that Sala sent a final message before the plane disappeared from radar around 20 kilometres (12 miles) north of Guernsey on Monday night.

"I'm on a plane that looks like it's going to fall apart, and I'm leaving for Cardiff," the 28-year-old said in a rambling WhatsApp audio message.

"If in an hour and a half you have no news from me, I don't know if they will send people to look for me, because they will not find me, you know... I'm so scared," he added.

The player's mother, Mercedes, told Argentine television channel C5N that the plane belonged to Cardiff chairman Mehmet Dalman, but he disputed the claim.

"I can say to you categorically that the plane had nothing to do with Cardiff City," he said.

Dalman said the club had offered to pay for his flight but Sala "made his own arrangements".

"I can't tell you who arranged the flight because I don't know."

Sala, who signed with the Premier League club on Saturday from French Ligue 1 club Nantes for a reported fee of 17 million euros ($19.3 million), was flying to Cardiff on a single-engine Piper PA-46 Malibu aircraft.

A 15-hour search Tuesday covering 1,155 square miles (3,000 square-kilometre) in the Channel spotted "a number of floating objects in the water", Guernsey police said.

Guernsey Coast Guard captain David Barker told AFP that the weather was expected to deteriorate later on Wednesday but added: "We'll certainly go until sunset today."

Their hopes rest in the possibility that the passengers are in a life raft, which has so far evaded detection.