The sale of Newcastle's port has been mired by accusations of bodged figures from the New South Wales Greens.

The Greens are accusing the NSW State Government of allowing the port corporation "a break" from paying superannuation, thereby boosting its perceived profits.

The annual report from the Newcastle Port Corporation shows it was $2 million ahead of its super payments in 2010/11, but experienced a dramatic turn-around to being underfunded by more than $5.6 million the following financial year.

Greens MP John Kaye says there was complicity to make the corporation’s profits looking higher than reality: “It looks to us like they've made the asset look much more attractive than it is to bring in a bigger price... the plan to sell off the asset did not come out of the blue, it was clearly in the minds of the government for some time... in the long run somebody is going to pay for this and it'll probably be the taxpayers of New South Wales... sooner or later that $5.6 million will come out of somebody's pocket.

New South Wales Treasurer, Mike Baird has insisted there will be no shortfall for employees' super at the Port of Newcastle, while admitting that no payments were made in the 2011/12 financial year.

He says independent advice found more funding was not needed, and so the corporation was not required to make contributions.

Some years there is less put in, other years there is more put in, it is a normal course of business,” Treasurer Mike Baird says, “the important point is whatever is required will be provided and the State Government does retain the ongoing obligation for employees superannuation.”