The Charity Commission says it has "serious regulatory concerns" about a Christian charity whose former employee stole £2.5m from it over a number of years.
Stephen Ashton, 62, from Dunstable, Bedfordshire, was jailed for five years and seven months this week after admitting stealing from Morris Cerullo World Evangelism in Hemel Hempstead, Hertfordshire.
Ashton, who worked for the charity in an accounting role for 16 years, was caught last August when another employee discovered he had been manipulating reports.
When Ashton's cabinets were opened, unpaid invoices, receipts for unheard-of companies and letters from debt collectors were found.
Prosecutor Robert Bryan told Luton Crown Court: "He abused his position of trust over many years by falsifying invoices and accounts to pay for his personal affairs, his lifestyle and that of others."
Ashton spent £500,000 on his mistress's mortgage and other gifts, including a £106,000 horse box, the court heard.
He also used it to fund a lavish lifestyle that included trips to New York and London, and helicopter rides.
He told the mistress, who lived in Newcastle, that his wife had died when in fact she was living in Dunstable.
Ashton, who earned £44,000 a year, was arrested at Birmingham Airport, having bought a one-way ticket to Tenerife.
The Christian charity submitted a serious incident report to the commission last year.
A commission spokeswoman said: "We have serious regulatory concerns about the financial controls put in place by the trustees and how this appalling crime could have happened without being discovered sooner.
"We are seeking further information from the charity as a matter of urgency and will be assessing its financial controls and oversight of those who work for the charity."
Morris Cerullo World Evangelism was previously part of the commission’s class statutory inquiry into double defaulters – charities that file their accounts late for two or more consecutive years.
According to the register of charities, it has filed its accounts late by more than 200 days on each of the last five years.
It had an income of £1.7m in 2015, accounts filed with the regulator show.
Julian Richards, European director of Morris Cerullo World Evangelism, said Ashton was a "trusted individual".
Richards added: "There is an active investigation by police relating to the recovery of assets, so we are not commenting further at this stage.
"I hope we get a clear picture of what is recoverable, then we can assess the full extent of the damage and comment openly."