Gmail users are finding their inboxes being emptied without rhyme or reason, with signs pointing towards a bug with Apple's recently released iOS 9 firmware update for the iPhone and iPad. This writer has encountered the problem as well, two days after installing iOS 9 on an iPad Mini 2.

Messages on the Gmail support forums have been responded to with claims that the bug has been encountered by those who have recently installed iOS 9, but Apple and Google have not publicly revealed whether they are aware of the problem or if it is true.

IBTimes UK has contacted both Apple and Google about the problem and is awaiting comment.

In response to a forum post written on 21 September, one user wrote: "Many people have reported the total loss of their email history possibly related to the Mavericks and Yosemite OS upgrades. It's also been reported with the iOS9 upgrade. It appears something corrupts or empties the email files on your computer and when the Apple email client or App sees everything is 'gone' it wipes the server also [your Gmail account]."

Another forum post given a similar answer can be read here. In January 2014, a similar problem occurred and was acknowledged by Google, as reported by The Huffington Post.

In the experience of this writer, only emails from the main inbox were deleted, with mail archived into folders still available to view. Emails have still been received by the account in the time since the inbox was first emptied.

Google has a system in place for missing emails, typically for accounts that have been hacked or compromised in some way. Whether it is able to recover the missing emails in this particular instance is not yet clear.