Another VW company has been found guilty of cheating on emissions.

Yet another shoe has dropped in the seemingly never-ending Volkswagen diesel emissions scandal with Germany on Thursday banning Porsche Cayenne Diesel and Macan S Diesel SUVs from being registered in the country.

German transport minister Alexander Dobrindt confirmed to Autocar that the country's KBA (Kraftfahrtbundesamt) has placed a registration ban on certain Cayenne and Macan diesel models after discovering an irregularity with the utility vehicles' emissions software. Testing by the KBA revealed that software used in the diesel SUV models could detect when they were undergoing testing and switch to a so-called "warm-up" mode that reduced CO2 output.

Both the Cayenne Diesel and Macan S Diesel use a 3.0L V6 diesel engine sourced from Audi. Audi used the same engine in several of its vehicles, including the A6 and Q7.

In addition to the registration ban, the KBA is also forcing Porsche to recall some 22,000 vehicles that are already on German roads.

"Porsche has detected irregularities in the engine control software during internal investigations and has actively pointed this out to the Kraftfahrtbundesamt (KBA), German Federal Motor Transport Authority. The irregularities are not related to the transmission control software. Corrections by means of a software update within the scope of a recall were agreed with the authority," Porsche said in a statement.

The company continued: "Regardless of the recall, Porsche continues to carry out internal audits on its vehicles and derive optimizations from them. Furthermore, the company is still in close contact with the authorities, in particular the German Federal Motor Transport Authority, on all current matters."

Porsche was forced to halt sales of the Cayenne Diesel in the United States in late 2015 after it was discovered that the vehicle's software was designed to skirt testing procedures.