He accused the government of being too quick to point the finger.
Consumer Affairs Minister Benoit Hamon released on Thursday details of an investigation into the firm which he said indicated Spanghero was the likely culprit in a scandal that has enraged consumers across Europe and implicated traders and abattoirs from Cyprus to Romania.
"I don't know who is behind this, but I can tell you it's not us. I'm astonished," Spanghero boss Barthelemy Aguerre told Europe 1 radio. "I think we will prove our innocence and that of my associates. I think the government has been too quick."
A French inquiry into how horsemeat got into ready meals sold across Europe found that the Spanghero firm labelled meat as beef when it knew what it was processing may have been horse.
Hamon said that Spanghero could not have failed to notice the meat it was importing was much cheaper than beef, and there was no indication that a Romanian firm supplying the meat had mislabelled what was in fact horsemeat.
Outside Spanghero's factory in the town of Castelnaudary near Toulouse in southwest France, workers were seen filling up dumper trucks with blocks of meat and sausages on Friday, although it was not immediately clear why they were doing so.
The privately-owned firm, which was founded by brothers of 1970s French rugby captain Walter Spanghero, has had its operating licence suspended for 10 days and will face legal action if the suspicions are confirmed.
The Paris prosecutor is now reviewing the investigation.
Aguerre said his company had analysed the meat as soon as the scandal broke and discovered that some had been a mixture of beef and horsemeat. "It shows that Spanghero is not behind this deception. It comes from elsewhere. It puts the 300-odd employees in a great deal of difficulty," he said.
Family name tainted
Hamon told the same radio station that it was not up to him to say who was guilty, but added that it was clear something was not right at Spanghero.
"There are sufficient facts which show that at the very least there was a lot of negligence," he said. "Millions of consumers have been duped so we had to act quickly."
The scandal, which has triggered recalls of ready meals and damaged confidence in Europe's vast and complex food industry, erupted last month when tests carried out in Ireland revealed that some beef products also contained horsemeat.
Laurent Spanghero, who sold the company in 2009 when it was in trouble for a symbolic one euro, said that while his family was not responsible, everything had to be done to save jobs in an area where there were few other employment prospects.
"My first thought is for the employees. It's long-term unemployment that is coming if we are not capable in the next three days of resolving this," said the tearful septuagenarian brother of Walter Spanghero.
"My second thought goes to our kids and grandchildren that carry our name. We have always taught them the values of courage and loyalty and today we have been plunged into dishonour," he said on television.
The British government and the European Union (EU) have called for a high-level meeting to investigate the scandal and it will be on the agenda of a February 25 EU farm ministers' meeting.
The European Commission has proposed increased DNA-testing of meat products to try to establish the scale of a scandal which has exposed just how many countries a portion of mince may have travelled through before ending up in frozen lasagne. – Reuters