The anti corruption group, Transparency Solomon Islands, says government land near the international airport that has been controversially sold to a local businessman must be handed back.
It says the land, which had been allocated to the Quarantine Department, is of national interest.
The watchdog says the sale is the latest in a series of questionable state land sales.
It says there is a well-coordinated system of sales re-sales influenced by personal interest and not the interests of the state.
TSI says the director of Quarantine, Francis Tsatsia was right when he said the land in question is of great importance given its proximity to the airport and the need to properly monitor animals and plants coming into the country.
TSI says the Solomons' leaders need to make decisions that are in the public and national interest rather than for their personal benefit.