The Government has ordered another witch-hunt after more leaking of sensitive documents - this time from the Ministry of Pacific Island Affairs, which questioned whether an inexperienced private company was a good choice for $4.8 million in funding.

Two other investigations are already under way into the source of leaks; the first was the Government's proposal to mine land protected in Schedule Four of the Crown Minerals Act; the second was plans to restructure the public service and merge Archives New Zealand and the National Library into the Department of Internal Affairs.

Pacific Island Affairs chief executive Colin Tukuitonga said an independent investigation would look at how a ministry briefing for minister Georgina te Heuheu on the Budget fell into the hands of Radio New Zealand.

"I need to assure myself, and our minister, that our staff have acted appropriately and in accordance with the state services standards of integrity and conduct," Dr Tukuitonga said.

The briefing outlined criticisms about the Pacific Economic Development Agency (Peda), which is finalising a purchase agreement with the Government to secure $4.8 million over four years for projects to lift Pacific people.

Radio NZ said the ministry's advice to Mrs te Heuheu was that Peda was "untested and unproven", had "not delivered on projects of any note", and "does not have a good record of working collaboratively with other agencies".