The Leicester City owner’s helicopter has crashed in a car park outside the club’s ground as it left the stadium following a Premier League match.
Vichai Srivaddhanaprabha was in the helicopter when it came down at about 20:30 BST on Saturday, a source close to the family has told the BBC.
One witness said he saw Leicester player Kasper Schmeichel run out of the stadium towards the scene of the crash.
It is not known how many other people were on board the helicopter.
Leicester had drawn 1-1 against West Ham United at the King Power Stadium.
The game kicked off at 17:30 and finished about one hour before the helicopter took off.
Under Mr Srivaddhanaprabha’s ownership, Leicester City won the Premier League in 2016, having started the season as 5,000/1 outsiders.
One Leicester season ticker holder, who did not wish to be named, said: “I saw Kasper Schmeichel run out first [from the stadium] and then loads of security guards and stewards.
“I was stood outside the ground but it crashed on the other side.”
Another witness said it appeared “the tail propeller wasn’t working, putting it into a spin”.
‘I have seen staff in tears’ – Reaction to Leicester helicopter crash
In the early hours of Sunday, Leicestershire Fire and Rescue Service’s Assistant Chief Fire Officer Andrew Brodie tweeted that he had just left “multiagency strategic meetings” at Leicestershire Police’s HQ.
He described the crash as “clearly serious and tragic”, adding: “Please don’t speculate on cause or who may be involved. Think of families, friends, responders, and @LCFC and their fans.” Media caption
Brief profile of Vichai Srivaddhanaprabha
Father of four
Billionaire and founder of duty-free consortium King Power International
Ranked as the fifth richest person in Thailand by Forbes Magazine
Bought Leicester City in 2010 for £39m
Under his ownership, the club won the Premier League in 2016 and reached the Champions League quarter finals a year later