A Europe-wide food fraud scandal over horsemeat sold as beef deepened as two companies at the centre of the row took legal action and governments said criminal activity was suspected.
Frozen food giant Findus lodged a legal complaint in France after evidence showed the presence of horse in its beef lasagne was "not accidental", while a French meat-processing firm said it would sue its Romanian supplier.
Romania - to where the horsemeat has been traced after a complex trail leading through Cyprus and The Netherlands that The Sun newspaper in Britain dubbed a "hoofdunnit" - announced an urgent inquiry into two abattoirs.
Britain said this week that the Findus lasagne and two meals sold by supermarket chain Aldi contained up to 100 per cent horsemeat, and products containing horse have subsequently been found in France and Sweden.
The consumption of horsemeat is particularly taboo in Britain, whose environment minister Owen Paterson on Saturday took the reins of a crisis meeting of retailers and officials amid growing public concern.
"This is a conspiracy against the public. Selling a product as beef and including a lot of horse in it is fraud," Paterson said after the meeting.
British authorities have said they are testing to see whether the horsemeat contains a veterinary drug that can be dangerous to humans. They have also refused to rule out that horsemeat could be found in school meals.
The Findus and Aldi meals were assembled by French food manufacturer Comigel using meat that was provided by Spanghero, a meat-processing company also based in France.
Spanghero in turn is said to have obtained the meat from an abattoir in Romania, via a Cypriot dealer who had subcontracted the deal to a trader in The Netherlands.
French frozen food company Picard said on Saturday it had also withdrawn two lines of lasagne made by Comigel for analysis.
Comigel chairman Erich Lehagre said it believed it was being supplied with 100 per cent French beef from Spanghero. "We are aware of the very strong feelings this has given rise to, particularly in Britain," he told AFP.
Findus initiated legal proceedings on Saturday but did not identify an alleged culprit, in a criminal complaint lodged against persons unknown with the authorities in France.
In Britain, Findus said it was taking legal advice over "what they believe is their suppliers' failure to meet contractual obligations about product integrity."
"The early results from Findus UK's internal investigation strongly suggest that the horsemeat contamination in beef lasagne was not accidental," it said in a statement.
Separately Spanghero - which was set up by two former French rugby players - said it would sue the Romanian supplier on the grounds that it mislabelled the horsemeat but refused to identify the supplier.
"We bought European origin beef and we resold it. If it really is horsemeat, we are going to go after the Romanian supplier," Spanghero chairman Barthelemy Aguerre told AFP.
But France's junior economy minister Benoit Hamon said that Poujol, the holding company of Spanghero, "acquired the frozen meat from a Cypriot trader who had subcontracted the order to a trader located in The Netherlands, who in turn was supplied by an abattoir ... in Romania."
Romania's agriculture ministry said Saturday that it would launch an inquiry into shipments of meat to France after French authorities said two Romanian abattoirs were implicated in the horsemeat scandal.
"If it finds that the meat came from Romania and that the law has been broken, the culprits will be punished," the Romanian ministry said in a statement to AFP, adding however that the origin of the meat had not yet been proven.
The lasagne scandal has blown up in the wake of a similar discovery last month relating to the content of "beef" burgers in Britain and Ireland, both countries where consumers have an aversion to the idea of eating horses.
On Saturday, the Cyprus veterinary service said it had launched a probe into whether burgers containing horsemeat have reached Cyprus from Ireland.
Horsemeat is still eaten in many parts of Europe where it is considered leaner and healthier than beef.
But food safety experts fear some unregulated meat could contain traces of a widely used veterinary painkiller, phenylbutazone, which can cause a serious blood disorder in humans in rare cases.