The Government should be wary of offering too much to developers in exchange for the Ngunguru sand spit, says the Environmental Defence Society.

Radio New Zealand reports that the Department of Conservation is investigating a possible land swap with Landco, the owner of the Ngunguru sand spit, to prevent development at the site.

But Environmental Defence Society spokesperson Gary Taylor says he is concerned that the department's Northland conservator recently described the spit as very valuable.

Mr Taylor says the spit should not be valued on its development potential because it has virtually none.

He believes Landco's subdivision proposals would never gain consent.