Customers of ASB Bank's Fastnet online banking service are facing excessively slow service for the next few days.
Customers trying to log onto their accounts are finding that they time-out before the log is completed.
A recorded message on the Fastnet help desk says the service is having problems which could affect the speed of the site. The technical support team is investigating a fix to rectify these issues and the bank hopes to get back to normal as soon as possible.
A Fastnet technician says the problem has been ongoing and will probably continue until early next week.