A German court Monday ruled in favor of an environmental NGO's lawsuit against the federal motor authority for releasing cars with software on exhaust gas recirculation it argues is illegal, in a judgment which could lead to a wave of recalls.

The NGO, Deutsche Umwelthilfe, is calling for Volkswagen Golf vehicles to be recalled because of software manipulation to emissions mechanisms, alleging the KBA authority should never have allowed these vehicles to be released to the market.

"The case was effectively successful," a court spokesperson said, meaning the decision by the authority to release the vehicles must be revoked.

The DUH is planning further cases against the KBA involving BMW, Volkswagen, and Mercedes-Benz vehicles which, if successful, could mean up to ten million cars which KBA authorized would need to be recalled, the NGO said.

Volkswagen said in a statement it would wait to receive the full reasoning of the court to decide on next steps.

The European Court of Justice last November backed the rights of environmental associations to take such actions against EU vehicle approvals on the basis of DUH's lawsuit, which was initially rejected by the Schleswig administrative court in 2017.

The ruling concerns software Volkswagen installed to control the recirculation of exhaust gases, which EU courts have said is illegal in certain conditions but Volkswagen views as in line with the law.