The woman seriously injured after she fell into a sinkhole at Whakarewarewa Village has thanked her rescuers.

The woman, a tourist from Perth, Australia, was airlifted to Waikato Hospital from Rotorua after falling into a sinkhole at the thermal attraction on Thursday last week.

"I would just like to state how wonderful all the people were who first came to my aid, getting me out and then pouring water on to my injuries until the emergency services arrived," the woman said in a statement.

"The care since then has been marvellous and I would like to express my thanks to all involved.

"At the same time this has been quite an ordeal and we would ask that my and our family's privacy be respected."

The sinkhole has been filled in at Whaka Village. Photo / Rotorua Lakes Council

The woman's husband also reportedly received moderate injuries trying to pull his wife from the sinkhole.

The sinkhole at the village has since been filled in with steam vents installed, with Rotorua Lakes Council saying repair work took place at the weekend.

WorkSafe is investigating the incident.

Last week, GNS Science volcanologist Brad Scott said sinkholes were a typical phenomenon in geothermal areas.

"Where there is high steam flow to the surface and that steam reacts with the shallow near-surface groundwater, acid solutions [form].

"The acid solutions alter the local rock and soils, this induces clay formation [that can be] washed from the local environment by water seeping down, especially under high-intensity rainfall."

Scott said the washing away of the clays and fine material would create a cavity and eventually collapse.

"Often there are no significant warnings and it depends on the ground surface in the area."

Scott said the collapse or the formation of a sinkhole was usually the end of the process.

"The cavity may have been forming for years. Once it is present it can be fenced off and made safe."