The unnamed man has been released on bail while a specialist data forensics team examines computer equipment that was seized from his home in Blackpool, according to antivirus firm Sophos.
According to Sophos, the man allegedly sent fraudulent e-mails claiming to be from Smile online bank and hoped that recipients would be fooled into disclosing their online passwords using a bogus Web site.
Graham Cluley, senior technology consultant at Sophos, said that phishing attacks are becoming commonplace as criminals attempt to steal unwary Internet user's passwords and credit card numbers and PIN numbers.
"Phishing is big business for internet criminals, and there can be few internet users who have not received a phoney email claiming to come from an online bank," said Cluley.
The UK's National Hi-Tech Crime Unit (NHTCU) was tipped off about the phishing scam in January by Smile, which is the online banking arm of the The Co-Operative Bank.
Detective chief superindent Les Hynds from the NHTCU refused to say how the phishing scam was traced back to the suspect but sent out a warning to potential phishers.
"The message is clear. Do not do this at home, we will find you. Anybody who thinks that they can copy the scam and get away with it is sorely mistaken," said Hynds.