The German luxury car maker and Volkswagen subsidiary stopped the sale of its vehicles in Europe over suspected non-compliance with environmental standards, German media has reported.

The halt in sales will last until Porsche adapts to the new WLTP test standards for vehicle emissions and fuel consumption, which will step into effect across the European Union in September.

According to the Frankfurter Allgemeine Zeitung newspaper, the new standards are meant to take into account of the ultrafine particles emitted by the new generation of direct injection gas engines.

When browsing Porsche's vehicle lineup on its website, a pop-up message appears informing shoppers that "The model you have selected is temporarily unavailable as a freely configurable new car due to an upcoming model revision." The message applies to Porsche's hybrid offerings as well. The company urges customers to get in touch with local dealerships to pre-order affected models during the transition.

The automaker has yet to make an official statement on the issue.