A Mercedes spokesman said the company's information was based on accounts by the test driver and by a driver in another test car.
"We positively assume that there was no excessive speed involved. The vehicle was in technically prime condition," he said.
His comments came to reports in the Swedish media about a woman who was killed in the Lapland region when she was struck by a Mercedes test car which had slid out of control on an icy winter road. The accident took place Tuesday.
Swedish prosecutors are now investigating the matter on grounds of gross negligence with fatal consequences. The victim was a mother of two children.