"I'm sorry." George Calombaris has finally spoken about underpaying his restaurant staff.

Celebrity chef and MasterChef judge George Calombaris has apologised for underpaying his restaurant staff in his first interview since the scandal broke this month.

Calombaris’ interview will appear on ABC‘s 7.30 on Wednesday night, during which he told host Leigh Sales he was “gutted” when he realised the extent of the underpayments.

“It takes a long time to build a reputation, in your case 25 years of work, and then you can lose it in a week,” Sales said to Calombaris in the interview. “What has been the toll of that on you?”

In response, Calombaris bowed his head for a long period of time as he gathered his thoughts.

"I love this industry," he finally answered with a shaky voice. "I really do, and I love every opportunity that it's given me."

It was 2017 when the tide began to turn on Calombaris' career after it was revealed that the reality star had underpaid 200 hospitality staff by $2.6 million.

Earlier this month, that figure was announced as much higher. It was reported that the 40-year-old had underpaid more than 500 employees by $7.8 million.

The Fair Work Ombudsman fined Calombaris and his Made Establishment company $200,000. Unions were disappointed by this result and called on the federal government to address wage theft penalties and there were also calls for Calombaris to be fired from MasterChef.

Less than a week later, he and his two co-judges Matt Preston and Gary Mehigan announced they were leaving MasterChef after 11 highly successful seasons after contract negotiations with Network 10 broke down.

"I won't forget that afternoon in 2017 when we sat there with my new business partners, after we'd done a full audit for the business, and discovered the underpayments," Calombaris said.

"I want to apologise to all my team, both past and present, for the effect I've had on them, we've had on them. I apologise to them."

He said his employees "are everything to us".

"I'm not here to blame anyone," he said. "I take full responsibility for this. I'm sorry."

Calombaris said that the speed in which his restaurants expanded meant his back end processes were not up to scratch.

"The thing about 13 years ago, you're a young chef, 26 years of age, you want to open your first restaurant, you get together with three other partners at that point, and you open the first one, then the second one opens, the third one, the creativity is flying, the ideas are flying, the dreaming is there.

"But the sophistication in the back end wasn't there.

"There was no CEO, there was no people culture manager, there was no elite finance team like we've got now, that can make sure that mistake that we made will never happen again."

He said he now wanted to be a "voice for change" within the hospitality industry.

He said the industry needed to make sure their processes were just as good as their food and service.

"They have to seek advice, they need to make sure they're on top of... the food, the service, the great wine, the great dishes, that at the back it needs to be just as delicious.

"Right now there's 642 team members that I absolutely adore. We aren't closing our restaurants, we're here. And it's my job as their leader to keep pushing forward and keep speaking this message, not shying away from the mistake we made, but also acknowledging that we fixed it."

George Calombaris' interview with Leigh Sales will air on 7.30 tonight.