Terrifying 15 metre-wide sinkhole opens up in retired Australian couple’s back yard

The couple have discovered they live above a disused mine shaft

A giant sinkhole measuring around 15 metres in diameter has opened up in a retired couple’s backyard over a matter of hours.

Neighbours alerted Lynn and Ray McKay to a hole they spotted in the back garden of the Queensland property on Monday morning, at which point it was one metre in diameter.

"Nine o'clock I got a knock on the door and it's the chap from next door,” Mr McKay told ABC News.

"I come out and I've got a hole in the ground, it was only a little one, a metre, and it's just got bigger since."

The hole continued to increase in size throughout Monday, growing to around eight metres across, until it reached 15 metres on Tuesday night.

The sinkhole is understood to have been caused by a collapsed mining shaft dating back to the 1880s, the Guardian reported.

The Mayor for Ipswich, Paul Pisasale, is keen to ensure the couple are rehoused and looked after while the sinkhole is dealt with. The McKays had previously lost their possessions in the 2011 Queensland floods which damaged their home.

“"It's not about local government or state government, this is about making sure that these two people know that they are not going to be left alone,” he told ABC News.