Sala, 28, was one of just two people on the plane, reports The Associated Press. The aircraft was en route to Wales from Nantes - where Sala had been a player since 2015 - when it vanished over the English Channel Islands.
No trace has yet been found of the plane or its contents, and Guernsey Police announced at noon ET on Tuesday that the search mission has been suspended until Wednesday morning.
"We can confirm Emiliano Sala was on board," said a spokesperson for the Authority, as reported by BBC Sport. "This morning, the French research started with one French national navy ship and one aircraft. The investigation will determine which authority will take the lead on the research."
The spokesperson added that the Piper PA 46 Malibu aircraft was French but was not registered in France.
Cardiff CEO Ken Choo said in a statement:
We were very shocked upon hearing the news that the plane had gone missing. We expected Emiliano to arrive last night into Cardiff and today was due to be his first day with the team.
Our owner, Tan Sri Vincent Tan, and chairman, Mehmet Dalman, are all very distressed about the situation.
We made the decision first thing this morning to call off training with the thoughts of the squad, management staff and the entire club with Emiliano and the pilot.
All of us at Cardiff City FC would like to thank our fans, and the entire footballing family for their support at this difficult time.
We continue to pray for positive news.
The plane left Nantes at 7:15 p.m. local time (1:15 p.m. ET) on Monday and had been flying at an altitude of 5,000 feet when it contacted Jersey air traffic control to request a descent. It then lost contact with ATC at around 2,300 feet and vanished from radar northwest of Alderney.
Monday night's search was called off due to worsening conditions before being resumed Tuesday morning.
A Channel Islands Air Search spokesperson told BBC Sport that red flares were reportedly sighted during a lifeboat and helicopter search, but "nothing of significance was found."
Channel Islands Airsearch chief officer John Fitzgerald told The Associated Press: "(I'm) not expecting anyone to be alive. I don't think the coastguard are either. We just don't know how it disappeared." He added that the plane "just completely vanished. There was no radio conversation."
As quoted by The Independent's Jack de Menezes, Nantes manager Vahid Halilhodzic told French newspaper La Voix du Nord: "It was already a delicate period. However, this, this is very difficult. We are waiting, but we are not kidding ourselves - we expect the worst."
As reported by BBC Sport, Sala's father, Horacio, told Argentinian TV: "I didn't know anything. I couldn't believe it. I'm desperate. I hope everything goes well."
His mother, Mercedes, added: "Here in Santa Fe, everyone is very emotional. We do not know what to think, it seems like a lie ... the town is in shock."