A fraud expert is warning people that a new phishing scam on Gmail could have serious consequences.

A large number of people took to social media this week to complain their Gmail accounts have been hacked. Google says it is investigating a phishing email that appears as someone trying to share a Google Doc with you.

It has warned people not to click the link and to report it as phishing within Gmail.

David Debenham, president of the Association of Certified Forensic Investigators of Canada, said there can be enormous implications to falling for these kinds of scams. Some viruses can watch every key stroke you make, allowing scammers to steal all your passwords and personal information.

"You can lose everything you own as a result of a phishing expedition like this," said Debenham.

"It's rampant. It's highly profitable to the crooks. They're highly organized and they're highly sophisticated as a result of about five or six years of learning curve in doing this."

People who think they have been hacked should reset passwords immediately.

You can avoid scams such as this by not clicking on links in emails. Instead type in web addresses yourself in a new window.

Google says it has taken steps to protect users from the attacks by disabling offending accounts and removing malicious pages.