The firm was involved in bringing Elton John to Stormont in 1998
New details on the financial ruin of a government-funded quango have been revealed by BBC Newsline.
The Northern Ireland Events Company was created to stage leading music and sports events.
However, it collapsed last year with debts of at least £1.6m despite having been funded to the tune of £2m-£3m a year by the taxpayer.
A confidential in-depth investigation by accountancy experts KPMG revealed irregular loans and payments.
The investigation also discovered a break-down in accountability between the Department of Culture Arts and Leisure (DCAL) and the board which ran the company.
A motocross event in Moneyglass ran up a deficit of £661,000.
The former chief executive of the NI Events Company, Janice McAleese, is engaged to the man who built the track, Joe Cockburn, but Miss McAleese told the investigators that at the time the decision was made to stage the event the couple were not in a relationship.
KPMG said there was no supporting documentation regarding Mr Cockburn's expertise and there was no tendering process.
According to KPMG, Ms McAleese's replacement, Jasper Perry, "was not adequately trained or qualified" for his role.
He left the company after just seven months.
During their tenures both Mr Perry and Miss McAleese had company credit cards.
KPMG said there was a "lack of supporting documentation to justify expenditure".
On one occasion, Mr Perry used the credit card to hire a car in the United States.
The cost had been agreed at $237 but $1,260 was charged to the card.
Investigators also queried why the events company paid off a horse show promotor's debt to a car firm.
The NI Events Company paid £17,618 to Charles Hurst in Belfast.
Ms McAleese authorised the payment, but she said it was an error. Previously she had told DCAL there had been no payment at all.
The peculiar financial arrangements operated by the company also included an unauthorised £200,000 overdraft in one bank account.
BBC Newsline said there were also different versions of some of the events company's financial paperwork.
Information filed at Companies Registry did not match the version sent to DCAL.
DCAL's figures showed finances within the level of an approved overdraft when this was not the case.
KMPG said: "We have evidence these accounts were modified by NIEC (Northern Ireland Events Company) but we cannot confirm who may have been responsible."
As to who was monitoring what went on, the board - which included well-known officials with experience of managing public money - told KPMG they sat at a strategic level with operational responsibility delegated to the chief executive.
DCAL assumed the NI Events Company's board of directors, described as "experienced in the public and private sectors," had proper procedures to check how money was spent.
The issue is likely to be the subject of much discussion in committee rooms at Stormont when MLAs finally get to see the report.
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