Humberside Police said it had received several reports yesterday about a man claiming to have run out of petrol.
The smartly dressed man was approaching other drivers, asking for money to help him to buy more fuel.
He offered victims a business card bearing details of a Dublin firm and an item of jewellery as collateral to reassure them that he would reimburse any money given.
Police said the man was using a black BMW and may have been in the company of a second man.
Issuing a warning on social media, they said the man gives the appearance of being a businessmen and his story seems entirely plausible on the face of it.
However, it is actually a scam which is being carried at different locations here in the UK and overseas.