Telstra's chief financial officer John Stanhope has added his voice to a growing number of people asking the government to present its business case for the National Broadband Network (NBN).

"Whether one gets done or not is not for me to say, but if you're asking for my professional finance view, then there should be a business case for any investment," Mr Stanhope told business leaders at the American Chamber of Commerce in Australia.

He added that Telstra has a business case for its own involvement in the network.

Several Australian business leaders, including TPG chief executive David Teoh, travel website Wotif founder Graeme Wood and Fortescue Metals chief Andrew Forrest have all demanded a cost-benefit analysis for the NBN.

Mr Wood told The Australian the project is nothing more than a "$43 billion hi-tech babysitter".

However, some analysts have pointed out that a business case would be very difficult to produce, as many of the benefits will be realised in the future.

Telsyte research director Foad Fadaghi told the Business Spectator: "If you had asked to consider the growth of Facebook 10 years ago, you couldn't even fathom the growth from that because it didn't exist. And it's the same situation here."

One benefit of the NBN for consumers has been the recent price war between Australian Internet Service Providers (ISPs) as broadband providers fight for market share ahead of the fibre roll-out.

Speaking to Fairfax, TPG's chief executive Mr Teoh admitted the NBN would be good for business, as the network would open up regional areas currently controlled by Telstra.

"The NBN will provide a level playing field in those areas so it will be another growth area for TPG because we will be extremely competitive from day one," he said.

The government has published an implementation study but has so far refused to release any further details of a cost-benefit analysis.