BP has confirmed that it had conducted tests and found that water had got into its stores at Macquarie.

A spokesman for BP said the company's claims service department was dealing with three customers whose vehicles had been affected.

''The torrential rain of recent times did cause some contamination at Jamison,'' he said.

''While we try very hard to prevent this happening there can, very occasionally, be contamination following severe storms.

''As soon as we were notified of the problem our procedures for this type of event were followed. The site was closed to allow checks to be made. The checks confirmed water contamination and the affected tanks were [ordered to be] cleaned-up, re-stocked and re-checked.''

The spokesman said the cleaning process was continuing.

''BP regrets the inconvenience caused to our customers by this event and we are investigating possible options which might prevent this from happening again.''

Motor Trades Association executive director Mick Gentleman said complaints about fuel quality were relatively rare.

''We have had no complaints made to the association. We have just under 300,000 registered motor vehicles in the ACT,'' he said.

''Last year there were 44 complaints to the Office of Regulatory Services and out of those none of them were about petrol or diesel.

''All of those complaints have been resolved.''

A spokesman for the Department of Sustainability, Environment, Water, Population and Communities said that diesel fuels were tested by the department, but not for reasons of consumer advocacy.