The estimated cost of the first construction phase of the world's largest radio telescope has jumped to 400 million euros ($530 million), the project's director general said Tuesday.

The increase of 50 million euros takes six years of accumulated inflation into account, and the figure could escalate further once additional costs of splitting the project between Africa and Australia are factored in.

The Square Kilometre Array (SKA) will be the world's largest and most sensitive radio telescope, with thousands of receptors spread over an area of a square kilometre (0.4 square miles).

Once completed, the project will allow astronomers to study distant galaxies in their quest to answer some fundamental questions about our Universe -- how it began, why it is expanding and whether it contains life beyond our planet.

The SKA will be able to detect a radio signal from a planet 50 light years away.

"What we are undergoing over the coming months is a review of how much Phase 1 will cost," Philip Diamond told AFP by phone from the English city of Manchester, where the SKA scheme is headquartered.

"What we are working towards is... presenting to the board at their July board meeting our informed estimates of the cost of the first phase of the SKA," he said.

"The board will then look at that, decide if they like it, and this will be part of the process then of going out to raise money from governments for the construction."

The project's original cost estimate, 1.5 billion euros in total for phases one and two, was made in 2007, and "we decided we should update the numbers to 2013 euros", said Diamond.

Members of the SKA decided last May to split the project between South Africa and Australia, which had both been bidding to be the host.

The decision has additional cost implications, which Diamond declined to specify but said was "not a significant increase".

Construction of Phase 1, which has yet to be approved, should start by 2016.

So far, about 110 million euros had been allocated to the project for the design phase currently under way, said Diamond, reporting on a board meeting held at the end of January.

"The Phase 1 money will come from the (partner) governments once we submit the proposals for design."

There are 10 full members -- Australia, Britain, Canada, China, Germany, Italy, the Netherlands, New Zealand, South Africa and Sweden.

India is an associate member aspiring to full status.