The true cost to taxpayers of the new privatised Northern Beaches Hospital has been revealed as $2.14 billion, more than twice the $1 billion figure publicised by health minister Jillian Skinner before the March election.

The NSW government is also accused of breaking transparency laws by suppressing the figure until after the poll and has been criticised for keeping secret key details of the landmark public-private partnership.

The contract with operator Healthscope was signed and announced by Health Minister Jillian Skinner on December 11.

Mrs Skinner said the hospital "will be valued at more than $1 billion" including $400 million in local road upgrades.

However, contract details published on Wednesday reveal for the first time that the private consortium, which includes Healthscope, Leighton Holdings and Theiss, will be paid $2.14 billion over the life of the contract until 2038.

This includes $600 million to construct the hospital.

The decision to allow a private operator to run the hospital was the focus of an advertising campaign by the NSW nurses and midwives' association during the election.

The advertising foreshadowed an unaffordable "Americanised" health system in NSW under a re-elected Coalition government.

Labor's health spokesman Walt Secord​ said it appeared there was an attempt by the government "to avoid public scrutiny of one of the state's largest health financial transactions".

"This whole hospital project was arranged under a cloak of secrecy to avoid public scrutiny," he said.

Under the Government Information (Public Access) Act summaries of large government contracts must be published within 45 working days of them "becoming effective".

Mr Secord said this meant the details of the Northern Beaches Hospital contract should have been published in mid-February, well before the March 28 election.

He also criticised the government for redacting key details of the contract for "commercial-in-confidence" reasons, including completion date, fees and penalty payments.

"This is a serious matter, and the Premier, the Treasurer and the Health Minister all have serious questions to answer," Mr Secord said.

On Friday, Mrs Skinner said the $1 billion figure quoted by her in December referred to the capital costs of constructing the hospital and associated road upgrades.

The $2.14 billion was the total payments by NSW Health to the private operator. "They are in no way contradictory," she said.

Mrs Skinner said she is "not involved in contractual matters". However, she said the "financial close" date for the contract - as distinct from the "contract close" date of December 11 - was January 28, which meant details should have been published by April 1.

The details were finally published almost one month after this date. But Mrs Skinner argued it meant publication "was always going to be after the election."

"There has never been a health Public Private Partnership that has been so transparent," she said.