Alun Lewis said he personally knew victims of online fraud
More than half the victims of e-crime do not report the incident to police, a survey has found.
The North Wales Police Authority survey found 57% of e-crime victims reported the incident only to their bank or credit card provider.
Vice chairman Alun Lewis said: "They were under the impression that the police could not do much about it."
South Wales Police said it had also found an under reporting of e-crime but that situation was changing.
The police authority covering north Wales estimates e-crime costs Welsh businesses around £294m a year.
It said the growth in the crime sector had led to some stolen cards or bank account details being bought and sold, sometimes for as little as 50p.
Mr Lewis said he personally knew people who had been victims of online fraud and it was important that all victims reported the incidents so police as well as the financial institution involved.
Police urge e-crime victims to report incidents to them
He said: "I appreciate that being the victim of any crime is distressing but it is very important that people get in touch so that we can allocate resources.
"E-crime can be just as upsetting as any other form of crime. It is one of the most intrusive crimes because in reality it's theft from your own home without you even knowing it.
"E-crime is also posing a threat to businesses across the region and a report published by the Federation of Small Businesses revealed that 54% of businesses have been a victim of fraud or online crime.
"It is vitally important that in order to have a proper picture in north Wales that people do feel confident enough to report crimes."
Last year the force appointed Det Sgt Andrea Barnard as its regional e-crime business liaison officer under the assembly government's
e-crime Wales initiative
In the South Wales force, the post is held by Det Con John Cherry. He said "We here in the e-crime Wales team recognise e-crime is under-reported and are working hard to improve awareness of the methods of protecting against this type of threat.
"If anyone feels they have been a victim of an e-crime they should report it to their local police station and in the case of a business they can additionally report their concerns via the dedicated e-crime Wales website."
In a statement, Dyfed-Powys Police said: "By talking to the business community, we are aware that under-reporting of this crime is happening.
"Since February 2009, we have to advise the Welsh Assembly Government of the number of instances of online crime reported to us, and we have seen a growth in the numbers in the last year."
Gwent Police have been asked for a comment.