Senate committee slams NBN roll out

A parliamentary committee has accused NBN Co of secrecy over future costs of rolling out the broadband network.

The Greens-Labor dominated Senate committee tasked with overseeing the NBN has produced a damning second interim report, accusing NBN Co of releasing a glossy version of its public corporate plan by omitting forecasts for financial years after 2014/15.

It also accuses the company of manipulating forecasts for political purposes.

Additionally, NBN Co refuses to divulge names of companies that have signed contracts and the "substantial new costs" incurred, the committee claims.

"This level of secrecy is unacceptable," the report says.

NBN Co is still too "uncertain" to reveal how much technology will cost or how long it will take to build, the report states.

"The Australian people are being kept in the dark by the minister and NBN Co on the cost and rollout timeframe of the NBN."

Government senators claim the report does not accurately reflect the current status of the NBN rollout.

In a dissenting report, they accuse some committee members of "calculated" behaviour to bully and intimidate key NBN Co executives.

"It is apparent the committee was established for the sole purpose of making rhetorical political points which have no basis in reality," coalition senators wrote.

The report recommends NBN Co release an unredacted version of its Strategic Review and the full version of its 2014-17 corporate plan.

It also wants an investigation into governance issues within NBN Co.