The forecourt of a Tesco filling station in Dorset has been dug up because drivers reported engine problems after buying diesel there.
Local press reports said that up to 100 vehicles broke down shortly after filling up at the service station at the Tesco Superstore at Branksome, Poole.
The site has now been closed and an excavator was seen at the forecourt but Tesco would not give further details of work taking place.
A Tesco spokesperson said: “We’re in touch directly with all the customers who are known to have been affected and we’ll ensure that customers are reimbursed for the cost of any necessary repairs.
“We know customers want to understand how the contamination happened and we are conducting an urgent investigation. This involves complex testing and we want to take the time to make sure we know exactly what happened. We will be back in touch with customers as soon as we have more details for them.”
The company said all the information it had pointed to this problem being confined to one petrol station only, and there was no evidence to suggest other petrol stations were affected.