German Transport Minister Alexander Dobrindt on Thursday announced a recall of Porsche Cayenne models equipped with 3-litre diesel engines after finding potentially illegal emissions controlling software in the vehicles.

Dobrindt told reporters he was withdrawing certification for the vehicles, which will need to undergo a software update.

Sports car maker Porsche AG is owned by Volkswagen, which in 2015 admitted to systematic manipulation of engine management software to cheat emissions tests, according to Reuters.

Porsche on Thursday said it had discovered “irregular” engine management software during an internal probe into emissions. Porsche also said it had agreed to recall the vehicles to fix the problem.

“The producer will of course bear 100 percent of the costs,” Dobrindt said. “There is no explanation why this software was in this vehicle,” Dobrindt said.

The minister said: “We have examined Porsche Cayenne vehicles of the 3 liter TDI Euro 6 Mark – during tests these vehicles deploy a so-called defense strategy, which isn’t activated in real traffic.”

“In our view that is a kind of test recognition, which we regard as an impermissible deactivation strategy.”