Audi has issued a voluntary recall for 850,000 cars worldwide that are equipped with V6 and V8 TDI diesel engines.
The free voluntary recall aims to tweak the software of affected cars, to improve their emissions in real-world driving conditions.
Audi announced the recall but has not yet confirmed the number of affected cars in the UK. The brand has been working with the German Federal Transport Authority (KBA) to implement the fix.
Audi said it would co-operate with authorities in their investigations, but avoided mentioning if any wrongdoing had yet been found. It did mention ongoing investigations by the KBA, with the possibility that if the German authority should find any discrepancies, further actions will be carried out.
Audi also said the recall will future-proof the affected cars against possible bans that might be implemented in the future.
The move by Audi follows a recall implemented recently by Mercedes-Benz that affects several hundred thousand cars in the UK and three million in Europe.