The helicopter belonging to Leicester City's owner crashed outside of the club's King Power Stadium on Saturday night after the Foxes' Premier League match.
More than an hour after the 1-1 draw against West Ham, the helicopter took off from the centre of the stadium's pitch, cleared the stands and crashed seconds later.
There were no immediate details about who was on board. In the past, Leicester owner Vichai Srivaddhanaprabha has used the helicopter on matchdays to travel between the stadium and London.
Officials from King Power, the Thai duty-free retail giant owned by Srivaddhanaprabha, told Reuters on Sunday they could neither confirm nor deny whether the billionaire was on board.
"We cannot say anything, and no statement can be given yet," one of the King Power officials said.
Srivaddhanaprabha bought Leicester City in 2010 for a reported £39 million ($50 million). Six years later, the club won the Premier League at odds of 5,000-1.
Pictures and video posted on social media on Saturday showed flames and smoke billowing into the air from the crash site near the stadium car park.
Sky Sports reported that the majority of fans had departed the area surrounding the stadium before the incident, though some people were still in the vicinity of the crash.
"Emergency services are currently dealing with an incident at the King Power Stadium, in Leicester, after an aircraft came down in a car park behind the ground earlier this evening," Leicester police said in a statement. "Officers are working alongside the ambulance service, Leicester Fire and Rescue Service, the Air Accident Investigation Branch and Leicester City Football Club to establish the exact circumstances of the collision."
A Leicester City spokesperson said: "We are assisting Leicestershire Police and the Emergency Services in dealing with a major incident at King Power Stadium. The Club will issue a more detailed statement once further information has been established."
Multiple clubs and players expressed their concern at news of the crash, while the Premier League tweeted: "Thoughts from all at the Premier League are with everyone affected by tonight's incident."
Leicester police said on Sunday that enquiries into the crash were expected to continue over the coming days.
"Leicestershire Police, East Midlands Ambulance Service and Leicestershire Fire and Rescue Service all responded to the incident last night and enquiries continue at the scene today, led by the Air Accidents Investigation Branch," they said.
"As soon as we are able to confirm any further details around the incident, we will do so."
Flowers and wreaths had been laid outside the stadium on Sunday.
Small bouquets of flowers, as well as wreaths, were left outside the stadium on Sunday by members of the public alongside a large image of the Hindu god Ganesh, which was also propped up among the flowers.
A small candle was placed in front of the flowers as people gathered at the stadium.
Information from Reuters and The Associated Press was used in this report.