Tasha Flaherty, of the Cotswold Water park Trust, reveals how she caught fraudster Dennis Grant

Tasha Flaherty, operational director of the Cotswold Water Park Trust, spoke exclusively to the Standard about how she tracked down evidence which led to the conviction of Dennis Grant who denied the charity of nearly £700,000.

In what whistle-blower Tasha described as the most dramatic three days of her life, she uncovered his fraud, confronted him and had him arrested by police.

It was due to the misfortune of one company which went bust that the criminal world Grant had been living in started to unravel.

Tasha's determination to expose the truth paid off last week as Grant was sentenced to four years and four months imprisonment for large-scale fraud.

His lies and deceit had gone undetected for two-and-a-half years but when Tasha joined the society in May 2009 as finance controller, Grant’s fate was sealed and he met his match.

Her suspicions were first raised in March 2010. The Kilbride Group had loaned £150,000 to develop Cleveland Lakes as a nature reserve and rowing centre. When Kilbride went into administration, the society was asked to refund the money, but Tasha realised only £50,000 could be traced.

Asking solicitors for bank transfer copies, she discovered the money was missing. It set her on a trail that would reveal huge sums of money which had been paid into a bogus account at a NatWest bank branch in Grant's home town of Banbury.

"The contract was completely new information to me," she told the Standard.

‘I searched but couldn’t find the account.

"I knew then I had to find out what was going on and get the details of a contract I knew nothing about."

She said she always suspected things were not entirely above board from the start but she said she could not put her finger on why. She said Dennis would rarely come into the office and liked to work alone.

"Dennis and Nick Hanson were two years behind with their accounts, nothing added up," she said.

"I had very little contact with Dennis and would not see him much."

In a bid to track down the information, Tasha, 38, told the late former finance director Nick Hanson that she was archiving all the accounts. She even took files home to privately investigate without fear of being caught and told only her mother what she was doing.

"She was the only person in the world I told my suspicions to and confided in," she said.

"I wanted to make sure that if I ever became ill or something happened, there was someone else who knew."

After lengthy investigations, she discovered Grant paid in CWPS cheques to the bogus account over which he had sole control, not the genuine account the society had with Lloyds TSB.

"When I found out what he was doing I just thought ‘Oh my God’," said Tasha.

"I went straight to the police but they said they needed more proof. I knew I had to get that proof and that I couldn’t let this one go."

She turned to former CWPS chairman Brian Atfield for advice and in a bold move she approached Grant at their Down Ampney offices and tackled him.

"I knew I had to tackle the bull head on," she added.

"When I confronted him he was doing all he could to avoid speaking about the fraud. He was trying to chat about other things and it was clear he was playing for time.

"I told him I was aware of the account in Banbury and I needed to access it.

"I gave him the necessary number to call and he pretended to scribble it down then had a phony conversation with the bank. He told me they would ring back but I could see that he hadn’t even dialled on his phone."

Grant said he would only talk if Nick Hanson was present. But the finance director was not willing to come to Cirencester and so Tasha and Mr Atfield drove to Nick's home in Coventry.

Before they left, Tasha described how Grant approached her and asked if he had any time left to sort the situation.

"I told him no time at all. His time was up," she explained.

"He asked if I was sure and I said yes, I was adamant he wouldn’t get away with it.

"I was never going to let this drop, after I knew what he was up to it was my responsibility to the society and to the staff to make sure to put a stop to it."

During the confrontation in Coventry, Grant asked Tasha if it would be sorted if he repaid the funds.

"I told him straight away, no. We went round in circles for about 20 minutes but eventually he realised I was not going to back down."

Grant finally accompanied Tasha to a local NatWest branch. She had the account frozen but not before realising the full extent of his fraud.

Just £2,300 of the £660,000 he stole was remaining.

When full bank statements were disclosed, they revealed the missing money had been spent on personal extravagances including a trip on the Orient Express, several expensive cars, a house in northern Cyprus and at shops including Marks and Spencer and Next.

She made sure both Grant and Nick handed over the paperwork along with their office keys, credit cards and mobile phones.

That was the last time she saw him until he appeared at Stroud Magistrates’ Court in April, charged with seven counts of fraud.

"Some will probably think I was stupid to get in a car with him but I had no choice," said Tasha. "I needed the proof the police needed and I was going to get it. That determination was going round in my head, nothing else was important at that stage."

With the evidence in hand, Gloucestershire Police's economic crime unit stepped in and Grant was arrested.

Tasha then called an emergency board meeting and explained the situation to the society’s shocked staff members.

"Looking back I must have been mad but for those three days I didn’t feel frightened or excited, it was just something I had to do," added Tasha.

"When I finally saw him in court I felt overwhelming relief. The pressure I had been building up had gone, I knew I had done it and that this man would get what he deserved.

"He completely underestimated me. I don’t think he realised I was capable of discovering what he had done but I proved him wrong."

Tasha said Dennis had cost the society more than money. She said for a period of time, people lost faith in it.

"It was difficult trying to regain people’s trust but I am hoping we are nearly there.

"The money he took would have enabled us to improve the Water Park but we never knew the money was there so we never had it in our budget.

"It was a bad time for us but we are moving forward now and the future looks brighter."

Matthew Millett, managing director of the Trust, paid credit to Tasha’s bravery.

"It was because of Tasha that Dennis was brought down.

"Tasha put herself at considerable risk in investigating what he was up to and called in the police," he said. "It was her diligence and detective work that led to the arrest and to Dennis’s conviction."