The French Aviation Authority has confirmed Cardiff City striker Emiliano Sala was on board a light aircraft that went missing near the Channel Islands last night.
The Welsh club's chairman Mehmet Dalman says they are very concerned, but are awaiting further confirmation.
The 28 year old Argentine striker completed a 15 million pound move from Nantes on Saturday and was due to report for training with Cardiff this morning.
Sala scored 12 goals in 19 Ligue 1 games for Nantes this season.
They were due to play in the French Cup tommorow, but the game has been postponed.