An elderly couple is waiting to find out when it will be safe to return to their home west of Brisbane after their backyard started to disappear down a century-old mine shaft.
Lynn and Ray McKay were put up in a hotel on Tuesday night while engineers watched over their disappearing backyard in Coal St, Basin Pocket.
Ipswich Mayor Paul Pisasale says the backyard was sitting over a disused mine shaft and he is confident the problem can be solved and the McKays will not lose their home.
"It's an exploratory shaft that goes down about 100 metres and there's no need to panic about a neighbourhood falling in, and we will take all the steps to get Lynn and Ray back in their house," Mr Pisasale told AAP.
Late on Tuesday, the Seven Network reported the sinkhole had expanded to about eight to 10 metres in diameter.
Mr Pisasale said the size of the sinkhole was always going to get worse before it settled but the McKay's and their neighbours need not panic.
"It was put in anywhere between 1903 and 1920. You can see this shaft was filled up with rubbish and bottles and whoever did it (filled it), didn't follow very good practices," Mr Pisasale said.
"It's the mines department's responsibility."
Mr Pisasale visited the home on Tuesday where he met with local engineers and the McKays.
He said it was an old part of Ipswich and the mine was about 40 metres from where it had been originally marked on the council's town planning maps.