German authorities announced on Tuesday that 24 samples out of 360 official tests carried out on meat had revealed traces of horsemeat as the scandal of horse mislabelled as beef spread across Europe.
"We have the results of 360 tests from the federal states, of which 24 tested positive for horsemeat," a consumer affairs ministry spokesman told reporters.
"It's too early to assign blame unilaterally... the authorities are working in the federal states to work out who should take responsibility," said the spokesman, Holger Eichele.
However, he said that the authorities would eventually be able to tell who were the "main culprits" and the "co-culprits".
"There are still a lot of tests in the pipeline," added Eichele, saying he believed there would eventually be more than 1,000 results to analyse.
"We are testing broadly -- not just ready meals but also suspicions in slaughterhouses" and food production centres, said the spokesman.
He said he was not aware of any positive tests in slaughterhouses.
Revelations in the past days have led to German firms becoming implicated in the horsemeat scandal.
On Tuesday, German firm H.J. Schypke was forced to deny that it had ever bought horsemeat after Swiss food giant Nestle cut off ties after discovering horsemeat in pasta dishes sold in Italy and Spain.
Nestle announced it was suspending deliveries of all products using beef supplied by the German firm.
But H.J. Schypke said in a statement that it was "exclusively a processing operation. We do not slaughter or chop up" animals.
"We buy all raw materials already chopped up, fresh or frozen, from certified suppliers... we would like to point out expressly that H.J. Schypke has at no time purchased horsemeat," it said.