The airport remains closed today and all flights have been cancelled following the serious incident at 4pm yesterday.
Police are due to hold a press conference this afternoon to issue further updates however it has now been confirmed four people have sadly died.
Essex Police said they were alerted shortly before 4pm on Sunday to “reports of a collision involving one 12-metre plane” at the airport, calling it a “serious incident” although there has been no confirmation of the number of casualties.
Images posted on social media showed a plume of fire and black smoke coming up from the crash site, while witnesses described seeing a “fireball”.
Zeusch Aviation, based at Lelystad Airport in the Netherlands, confirmed its SUZ1 flight had been “involved in an accident” at London Southend Airport.
The statement said the company was “actively supporting the authorities with the investigation”, adding: “Our thoughts are with everyone who has been affected.”
Zeusch Aviation’s website says the plane can be used for medical flights to transport patients or organs.
An Air Accidents Investigation Branch (AAIB) spokeswoman said: “The AAIB has started an investigation into an accident involving an aircraft near Southend Airport which occurred yesterday afternoon.
“A multi-disciplinary team including inspectors with expertise in aircraft operations, human factors, engineering and recorded data arrived at the accident site yesterday afternoon.
“Inquiries are ongoing today.”