There are genuine fears that Emiliano Sala, the Argentinian footballer who signed for Cardiff City last Saturday, was on board a private plane that disappeared near the Channel Islands on Monday evening.

Emergency services have reported that a small plane – a Piper Malibu – travelling from Nantes to Cardiff went missing near the Casquets lighthouse, and there are concerns that Sala was one of the two passengers.

Cardiff’s chairman, Mehmet Dalman, said: “We are very concerned by the latest news that a light aircraft lost contact over the Channel last night. We are awaiting confirmation before we can say anything further. We are very concerned for the safety of Emiliano Sala.”

A search and rescue operation took place in the area on Monday evening amid poor conditions. HM Coastguard has said that the disappearance was not in the search and rescue area but that it had sent two helicopters to assist Guernsey Coastguard. A spokeswoman said: “HM Coastguard helicopters from Solent and Newquay have been helping to search overnight with nothing found.”

Sala completed his move from Nantes to Cardiff on Saturday but then returned to France to say goodbye to his teammates. He was set to train with Cardiff for the first time on Tuesday morning and expected to make his debut against Arsenal next week. The 28-year-old, who has scored 12 goals in Ligue 1 this season, joined Cardiff for a club-record fee, believed to be £15m.

Guernsey Coastguard received an alert at 8.23pm on Monday that a light aircraft had gone missing and searches were carried out until 2am, at which point conditions forced a halt. The search resumed at 8am and Guernsey police said that as of 10.20am there were two helicopters, two planes and one lifeboat searching the area.

Police said the aircraft had requested descent on passing Guernsey but that Jersey air traffic control lost contact with it when the plane was at 2,300ft.

Sala’s former club Chamois Niortais tweeted: “Tell us it’s a joke... Emi.... All the TeamChamois thinking of you.”