A Wrexham-based dairy firm employing 330 staff has gone into administration.
Farmers were told Tomlinsons Dairies in Minera could no longer process their milk and to find a different processor.
PwC confirmed on Tuesday that it had been appointed administrators for the firm, which also has operations in Chester and Shropshire.
One worker said "devastated" staff were called into a meeting on Monday, while solicitors representing some said they may pursue legal action.
In a statement, Tomlinsons said: "The family shareholders, directors and management of Tomlinsons are devastated by the administration and sincerely regret its impact on their customers, suppliers, farmers and employees."
A spokesman for the administrators said Tomlinsons had "suffered an accumulation of significant operating losses over recent years" made worse by problems like energy costs and a depressed cream price.
"Our thoughts are with the employees affected and we have ensured a range of support measures are available to them at this difficult time," he said.
A Welsh Government spokesman said it has established a "taskforce to work with the staff affected by the closure" of the Wrexham factory.
"We are in discussions with farming unions and other stakeholders to consider what support is required at this difficult time," he said.
"We have worked closely with Tomlinsons dairy over the last 18 months to try to help them resolve their ongoing business issues."
A worker, who did not want to be named, told BBC Wales that employees called into Monday's meeting were "really devastated".
Meanwhile, solicitors representing some of the workers said an investigation was being held to see if the company "had failed in their legal obligation to undertake a collective redundancy consultation process," which would mean staff could be entitled to compensation.
In May 2017 the company, which had an annual turnover of about £45m, said it was creating 70 new jobs following a £22m investment at its Wrexham dairy
Tomlinsons was employing about 170 staff that year and planned to create 70 more jobs with its expansion.
The business was established in 1983 by brothers Philip and John Tomlinson, expanding from a doorstep round using milk from their family dairy farm in Minera.
Farmers were told the news in phone and text messages on Saturday that Tomlinsons could not accept their supplies.
However, they were given the name of three other milk processers who could accept their milk supplies.
Two of the milk processors have told BBC Wales they had agreed to take milk supplies from 20 farmers who have been affected.
Wrexham dairy farmer Keith Thompson said he found a buyer in Lancashire to accept his milk supply on Sunday.
"It is one hell of a blow," he said.
"The ramifications for the rural economy around Wrexham is horrific."
Fellow farmer Les Morris said he and neighbouring farms were "on edge".
"We don't know what is happening from day to day," he said.