New Zealand has failed to convince a scientific panel it is best suited to host the world's largest radio telescope, after the panel recommended the $2.5 billion project be awarded to a rival consortium led by South Africa.

A joint New Zealand and Australian consortium is bidding against a southern African group for the right to host the Square Kilometre Array (SKA), a $3.1 billion cluster of radio telescopes dubbed the "biggest science project in the world''.

But the SKA Site Advisory Committee compiled a confidential report last month which judged the South African-led bid as stronger.

The final bid decision was due to be made on April 4, but papers leaked to the Sydney Morning Herald showed the option to spread the array across eight nations in southern Africa was a better bid, in part due to lower costs to power the telescope and then transfer the data.


The final decision now rested on a vote of four countries represented on the board of directors for the project.

China, Italy, Britain and the Netherlands, would vote on the final location, but the leaked report was seen as a major setback to New Zealand and Australia's hope of winning the project, the Sydney Morning Herald reported.

Sergei Gulyaev, head of AUT University's Institute for Radio Astronomy and Space Research, last month said one of the tantalising prospects of the radio telescope would be its ability to give a "bird's-eye view'' of the tectonic plates deep under New Zealand.

The Russian-born scientist said the radio telescope could use "quasars'' - stable points on the edge of the universe - as a frame of reference for measuring the most minute changes on Earth.

"By observing quasars on the border of the universe, we create a fundamental reference frame in which we can study all the irregularities of the rotation of the Earth, ocean, tides, and solid earth, and the way an island like New Zealand is breathing.''

The New Zealand/Australia bid has earmarked locating the bulk of the array in Murchison Shire, a vast outback area in Western Australia north-east of Geraldton, which has no mobile phone towers or other human activity to interfere with the signals.

In New Zealand's South Island around 25 to 50 antenna dishes would contribute to the array, in areas yet to be identified.

It's too early to determine whether dishes would be situated in the North Island.
Construction of the array is set to begin in 2016.