Then the South Bank Corporation became interested in getting their hands on them.

However, by Tuesday afternoon they had been sold to the Caboolture Historical Society.

The society runs the four-hectare Caboolture Historical Village, just north of Caboolture on the Bruce Highway.

Peter Rasey, the chairman of the Expo 88 30th anniversary People's Committee, suggested they could be erected at the new Port of Brisbane cruise ship wharf.

“If the state government were of a mind, they could definitely reimagine the sign and some parts of the sign could be salvaged and incorporated into a brand new ‘Welcome to Brisbane’ statement,” Mr Rasey said.

“Sydney has the Harbour Bridge, Melbourne has West Gate Bridge," he said.

"What better than for Brisbane to have the ‘Australia’ sign welcoming visitors?"

A spokesperson for Port of Brisbane said although they were determined to ensure the Brisbane International Cruise Terminal was an entry statement all the city's residents could be proud of, the facility didn’t have the scope to include Ken Done’s famous artworks.

“Our main focus is to provide a world-class passenger experience that facilitates increased cruise tourism for the region,” the spokesman said.

The South Bank Corporation had shown interest in the signs. Chief executive Bill Delves told the ABC that the discovery of the signs sitting in the paddock at Arethusa College in Deception Bay could be used for the 30th anniversary of the Expo 88, which drew millions of international visitors to Brisbane during its staging from April to October in 1988.

“How could we not consider something so iconic in such an iconic location?” he said.

The signs had been positioned outside the Australia Pavilion at Expo and were among the most photographed artworks at the event.

Radio 4BC reported that the Caboolture Historical Society and a local business figure had joined forced to preserve the signs.

Arethusa College declined to comment on the decision to sell them.