Farmers insist that price rises were not passed onto them
Sainsbury's and Asda - along with a number of dairy firms - will be fined at least £116m after admitting fixing the price of milk and cheese.
Farmers whose livelihoods depend on dairy have been giving their verdict on the news.
The relationship between supermarkets and the agriculture industry has never been an easy one.
But the admission by two chains that they colluded to keep the cost of milk and dairy products artificially high exposes the lack of trust between the two sides.
The supermarkets may claim that they were trying to help beleaguered dairy producers.
But many ordinary dairy farmers ask where exactly this extra cash went.
Andrew Hemming, who farms his dairy herd in Hockley Heath, near Solihull in the West Midlands, insists that the price rises were not passed on to farmers.
"It's been a very grim time for everyone involved in the business," he says. "It would have been much easier for me to sell up, but I love what I do too much.
"It's only now that the price of milk has increased enough that it actually covers production - so nobody is able to invest.
"I want to know what will happen to this fine. The production side of the dairy industry has lost considerably more than the £116m that the supermarkets have been levied."
Jonathan Owen, 29, was the third generation in his family to take over a farm in Hope, Flintshire, after his father's death in 2002.
But in March 2007 he was forced to sell up, blaming the low price of milk.
"To be honest, it's not the supermarkets who I blame - it's the government," he says.
"They're the ones who are ultimately responsible for the state of agriculture in this country.
"But it is encouraging to know that something is being done about it."
Others are concerned about the impact on the image of farming.
Andrew Halhead, 52, who lives near Lancaster, worries that the public have a false impression of how well producers are coping.
"Consumers have seen the price of milk rise over the past few years, and they've assumed that farmers are benefiting," he says. "But that isn't the case.
"So many people are getting deeper into debt and dropping out altogether.
"At least now the chickens are coming home to roost for the supermarkets - they pushed so many people out of business that now the supply chain is smaller, and they're finally having to pay us a bit more."