Google said on Monday that it is continuing to investigate a problem with its Gmail service, which reportedly caused some users' emails being all erased.

The issue popped up over the weekend as users reported on online forums that they had lost emails and other information within their Gmail accounts.

Google confirmed the problem Sunday on the company's website that provides status reports of its Apps services, initially saying that the issue affected less than 0.29 percent of Gmail users.

It then twice revised downward estimates of the number of users affected to 0.08 percent and then to 0.02 percent.

"Access has been restored for one third of the affected users," Google said in a latest notice Monday morning, adding that the remaining accounts are being restored on an ongoing basis.

"We expect the issue to be resolved for everyone within 12 hours," Google said.

The Gmail failure reinforces danger of becoming too dependent on the so-called "cloud", or storing and processing information through the Internet, a post on technology blog TechCrunch on Monday noted.

"It's just another example of why moving your entire life to the cloud may not always be the best idea," the post said.