BERLIN/PARIS (Reuters) -- The German transport ministry has no evidence that any carmakers other than Volkswagen have manipulated emissions tests, a spokesman said on Friday.
"At this point we have no indication of other manufacturers being involved," the spokesman said at a government news conference.
Separately, authorities in France, Italy and Switzerland took action against the automaker on Friday for using a so-called "defeat device" in vehicles sold in the countries.
Prosecutors in Paris have opened a preliminary inquiry into suspected "aggravated deception" by VW, an official from the prosecutor's office told Reuters on Friday.
The move adds to the legal burden the German carmaker faces after U.S. investigators found that it had cheated on diesel emissions tests.
France's consumer protection code allows for prison sentences of five years and a fine of 600,000 euros ($669,600) for aggravated deception, the prosecutor's office said.
French consumer protection and fraud control authorities have launched a separate investigation on whether VW cheated on emissions focusing in particular on vehicles software devices.
The results of that probe, which is not a penal investigation, are expected in November or December.
Volkswagen has said there were 946,092 vehicles in France equipped with the EA 189 engines affected by the emissions data manipulation carried out by the company worldwide. A total of 11 million vehicles are affected globally.
Italy's antitrust body has opened a probe into possible commercial wrongdoing by VW Group.
"Consumers might have erroneously made their purchase decisions based on the emissions claims made by Volkswagen," the antitrust watchdog said in a statement on Friday.
It did not say how long it expected its investigation to last.
Volkswagen has said some 650,000 cars sold in Italy carried the software that was designed to cheat diesel-emissions checks.
The Swiss Federal Roads Office on Friday issued a preliminary ban on registering new VW Group diesel vehicles that may be outfitted with software designed to cheat emissions tests, it said in a statement.
The agency also banned registering newly imported used vehicles affected by the manipulation scandal. Friday's announcement does not apply to used VW vehicles already on the roads in Switzerland.
Up to 129,000 VW Group vehicles registered in Switzerland are affected by the rigged emissions testing scandal, VW's Swiss distributor AMAG has said.
AMAG has already halted sales of new VWs affected by the manipulation.
VW Group said Thursday that its investigation into rigged diesel engines will probably take months to complete. The group will work closely with U.S. law firm Jones Day to unravel how software to cheat diesel-emissions tests was developed and installed for years in millions of vehicles, the Wolfsburg-based company said.