Drivers have been left high and dry after contaminated petrol sold at a service station in Melbourne’s east brought their engines to a standstill.

The watered-down fuel, sold at 7-Eleven on Hawthorn Rd in Nunawading, left a number of drivers with big damage bills, with the cause still being investigated.

“All these cars, every single one that is here is ruined because of water in their fuel,” one customer said.

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The engines on each car that filled up at the fuel station broke down moments after filling up with some failing to even start.

“Cars were just dying ... immediately once they started running with the fuel that was put in,” another customer said.

“Diesel, 98 is totally stuffed and 91,” customer Michael Hennessey said.

“We’re telling the people who are running the store to stop pumping fuel, stop selling fuel and they just continue to do it.”

7NEWS understands multiple pumps at the site were affected by contaminated fuel on Saturday afternoon.

The cause is yet to be confirmed however it’s believed the heavy rain that has recently hit Melbourne could be to blame with water leaking into its tanks.

7-Eleven said the issue was isolated to just the one store, where fuel sales were suspended as the company investigated the cause.

Impacted customers will be contacted and offered compensation.