The email sent to NAB customers tells recipients their bank account has been disabled and prompts them to click a link to reactivate their account.

The email sent by scammers. Photo: Mailguard

The link takes the recipient to a very realistic, but fake, copy of NAB's banking website, which is designed to harvest the victim's account ID and password.

NAB said late on Thursday night that the fake website had been removed.

A screen shot of the fake website through which scammers try to obtain online banking details. Photo: Mailguard

A NAB spokeswoman said the bank had issued a take-down notice to have the fake website removed after it became aware of the scam.

"We remind customers, NAB will never ask you to confirm, update or disclose personal or banking information via email or text," she said.

The email comes with the subject line 'Notification' and is sent from discharge.authority@nab.com.au.

MailGuard CEO, Craig McDonald, said the company had blocked the distribution of thousands of copies of the email on Thursday afternoon.

"A phishing scam is a fraudulent attempt to steal your information or identity for financial gain. In this case, the perpetrators want victim's banking details," he said.

"Creating a fake website allows them to collect peoples' account number and passwords without arousing suspicion.

"That valuable information is collected and used to make future unauthorised transactions."

Many NAB customers have taken to Twitter this week to ask the bank whether the email was a scam.

NAB has listed the scam on its website, and advised customers to forward the email to spoof@nab.com.au and then delete it.

Victims are urged to contact their local NAB branch, or call 13 22 65 immediately.