According to The Times, the losses incurred at the 1966 Golden Anniversary Gala Dinner were due to poor ticket sales and the cost of entertainment, which included an appearance by the pop star Lulu.
The charities involved are not believed to have suffered losses because the event’s costs were borne by the businessman Carl Holness, whose company 66 Winners organised the dinner.
According to the company’s website, 66 Winners was established by Holness earlier this year to hold events celebrating the 50th anniversary of England’s World Cup victory in 1966.
The fundraising dinner was held on 30 July at Wembley stadium and attended by surviving members of the World Cup-winning England team. Tickets to the event cost either £250 or £159, the 66 Winners website says.
A spokesman for WellChild said: "WellChild was initially selected as one of the beneficiary charities for the 66 Winners fundraising event at Wembley, but eventually we were not involved in fundraising on the evening.
"We were not involved in the running of the event and so are unable to comment on the organisational or financial matters surrounding it."
Children In Need did not respond to a request for comment in time for Third Sector’s deadline, and Holness could not be reached.