Drivers are being warned not to hand over money to a motorist who claims he has run out of petrol to get cash.
The man was seen five times on March 20 attempting to flag down motorists on roads in the county.
Two drivers who pulled over were suspicious and called police.
Humberside Police said the first case happened where the A164 joins the A1079 at Beverley.
The man flagged down a driver at 12.10pm and asked for money for petrol.
At 1.48pm, a man called police to say he had seen the same man attempting to flag down motorists three times that day – near Beverley Westwood, between Willerby and Beverley and at Market Weighton.
Another driver called police at 2.39pm to say he had stopped for a broken down vehicle on the A63 at North Ferriby.
The driver claimed he had run out of petrol and offered a ring and a business card in exchange for cash.
A force spokeswoman said: "Police believe that these reports are connected and would ask people to be vigilant and not to give people any money or any valuables in these circumstances."
Call police on 101 if you have any more information on these incidents.
