A drastic reduction in staffing at Tekapo's Mt John Observatory is threatening the facility's ability to contribute to international research, a former director says.
All but one member of staff have retired from the observatory, which is the centrepiece of a tourism industry around the Aoraki Mackenzie International Dark Sky Reserve.
Dr John Hearnshaw said of all Organisation for Economic Co-operation and Development countries, only New Zealand and two others did not have a national facility.
"The four BRIC countries - Brazil, Russia, India, China - all have huge national observatories," he said.
"Many developing countries do. Now New Zealand has got to join the ranks and do its bit for optical astronomy."
The observatory had international research contracts and helped attract students to the country to study astronomy, Dr Hearnshaw said.