The new leader of Northampton Borough Council says he has learnt lessons after his business went into liquidation owning thousands to the taxman.
Documents emerged on social media this week, detailing the liquidation of his company, Individual Team Performance Limited, in 2014.
In a report by the liquidator dated June 22, 2016, Councillor Nunn was criticised for "repeatedly failing to provide evidence of his financial worth" in order for the liquidator to establish whether it was worth pursuing him for funds withdrawn from the company when it was insolvent.
Councillor Nunn, speaking to BBC Northampton this morning, said it had been a time of "enormous personal stress" and that he had learnt many lessons from the experience.
Last week, Councillor Nunn told the Chronicle & Echo he was a "changed man" following his conviction for domestic violence in 2004 which almost led to the end of his political career.
Councillor Nunn took over as leader after Councillor Mary Markham resigned over a row concerning the future of the Barn Owl pub.
Speaking on the Stuart Linnell breakfast show, Councillor Nunn responded to the criticism that he had initially failed to provide information to the liquidator. A later update from the liquidator said the information had "now been provided".
"It was an ongoing process and if I am honest, perhaps there are listeners who have experienced the same thing, it comes with a great disappointment and a feeling you have failed and ashamed, if you like, it was reported on and people knew about it but nevertheless your first feeling was to find a way to repay it," he said.
"I provided some information, I would have preferred to have recovered the money to pay it, but ultimately I didn't. I provided the information I could that was required, which didn't paint a pretty picture. You don't get to a stage of liquidating a business before things get pretty terrible.
"There are lessons to be learnt about things and I have learnt a lot of lessons from this, one of them is that you have got to learn when to stop.
"You feel a certain preciousness about your baby and your business that you have spent a lot of time building. There is a time that it is time to stop and I should have done that a long time before but you don't reach a point when you think about liquidation until you have absolutely done everything you can and actually you are in a hell of a mess by then. Other people will know this."
Councillor Nunn said he had found himself in the spotlight as a result of Councillor Markham's resignation and the role was "not far off a full-time job".
"The flip side of that is that it gives you a certain profile and it may bring out things that you do not want to necessarily sit and talk about and this is the situation I find myself in right at this moment," he said.
His experiences, he said, meant he could now appreciate the difficulties businesses find themselves in.
"I have had a fuller life than most and I have had the highs and lows and I have made mistakes and I am absolutely committed to Northampton.
"There is nowhere more under scrutiny than Northampton Borough Council at the moment. I haven't slept a lot at times, I have to tell you too, and some of that is about worries and some of that is about time," he said.
Councillor Nunn concluded the interview by stating: "I am going to do my best to turn this town around."