It's being called Australia's TV bombshell of the year.

After 11 years of delivering big audiences, and significant revenue, the Channel 10 network had decided to let its three biggest stars walk out the door.

The three judges of MasterChef, Gary Mehigan, Matt Preston and George Calombaris, will not return for the next season.

Former TV executive and host of the TV Blackbox podcast Rob McKnight told Heather du Plessis-Allan that this has stunned and surprised the Australia television industry. 

He says that the struggling Channel 10 did not want to see this day comes as they know how successful the show is. 

"It's one of those few shows that the network knows will work and will deliver an audience."

Controversy has surrounded Calombaris over the fact he has underpaid his workers by about $7.2 million. 

McKnight says that there was pressure to drop him from the show, but it would have seen all three go. 

"The three judges are like the Three Musketeers. If one goes, they all goes."

He says there are rumours that CBS, which owns Channel 10, did not want to pay the 40 per cent wage increase the three judges reportedly wanted. 

• 'Just desserts': MasterChef judge slammed after exit
• All three MasterChef judges to leave show in mass walkout

The three judges are all telling different stories on social media, which McKnight says shows the judges did not expect to go.