Spanish car manufacturer Seat said 700,000 of its cars were fitted with the EA 189 diesel engines in which Volkswagen has said there are "discrepancies".
Seat said the cars were sold worldwide and it was seeking to determine how many were sold in each market.
Also fitted with the suspect software were 5 million VW brand cars, 2.1 million Audis and 1.2 million Skodas.
Seat and Volkswagen-Audi Spain ordered a suspension of sales of all Seat, Volkswagen, Audi, Skoda and Volkswagen commercial vehicles with the EA 189 diesel engine. It said this decision would affect 3,320 vehicles currently in stock.
In Brussels, European Union Industry Commissioner Elzbieta Bienkowska was scheduled to meet with Volkswagen brand chief Herbert Diess.
"We expect Volkswagen to explain the situation," said EU spokesman Ricardo Cardoso. "The commission wants facts and wants to get to the bottom of this."
The German government last week set up a commission of inquiry on the scandal. Transport Ministry spokesman Martin Susteck said that the panel is in contact with the US Environmental Protection Agency.Volkswagen's commercial vehicles division has said 1.8 million of the German giant's vehicles are among those affected by the emissions-rigging scandal.
Volkswagen AG has admitted using a piece of engine software to cheat on diesel car emissions tests in the US. It said last week that the engines concerned are in some 11 million vehicles worldwide - far more than the 482,000 originally identified by US authorities.
Details have emerged gradually of how many were made by which VW division.
On Tuesday, Guenther Scherelis, a spokesman for the commercial vehicles unit - which makes vans and pick-ups - confirmed a report in the German daily Hannoversche Allgemeine Zeitung that 1.8 million of its vehicles were affected. He did not give further details.
Also affected are 5 million VW brand cars, 2.1 million Audis and 1.2 million Skodas.
