The governing body of UK showjumping says it is extremely disappointed with Baker Tilly, which has handled its financial affairs for 18 years. A letter to members the BSJA said: ‘We feel Baker Tilly has been extremely unhelpful about this matter and your board felt they had totally lost confidence in them and invited Baker Tilly to resign as auditor, and they have now done so.’

The BSJA, which regulates more than 4,200 horse shows a year, including The Horse of the Year Show, believes the error should have been picked up earlier.

The error was unearthed during a review by chief executive Diana Cornish, the BSJA claimed. Its income and net asset value was overstated because charges to members and show organisers were incorrectly passed to the financial reporting system.

Baker Tilly declined to comment.