By James Oliver
Producer, BBC Panorama
Robert Appleton's Procurement Task Force was set up in January 2006.
The Task Force originally focused on allegations against eight members of staff who had been suspended in 2006, including Sanjaya Bahel.
It is not clear how long Appleton's Task Force will survive
They've investigated allegations of corruption in UN peacekeeping operations around the world including Ethiopia and Eritrea, the Democratic Republic of Congo, Kenya, and Haiti.
Between January 2006 and January 2008, the Task Force had completed 132 cases, but still has almost 300 cases to investigate.
It identified 15 'significant corrupt schemes' involving UN contracts worth an estimated $630 million (£350 million)
Thirty-two companies from countries including Britain, the United States, New Zealand, India, Russia, France, Italy, Kenya, Canada, Cyprus, Ireland and the Congo have been banned from doing business with the UN.
It identified 15 UN staff as having committed criminal offences, 12 of whom have been referred for prosecution with the relevant national authorities, while 27 staff have been charged within the UN with misconduct.
Five staff have been dismissed and 10 have been suspended.
Crimes identified by the Task Force include fraud, bribery, bid-rigging and money laundering.
The Task Force is now investigating allegations of 'forged bids', 'fraud', 'gross mismanagement', 'favouritism', 'collusion' and 'misappropriation' in Iraq, Sudan and within the United Nations headquarters in New York.
But it is not clear how long Appleton's Task Force will survive.
It faces hostility from some member states who fear their officials have been unfairly targeted, something the Task Force adamantly denies, or who believe that it primarily targets UN staff members from the developing world.
Despite this, the General Assembly recently confirmed funding for the Task Force until the end of 2008.
However, under the proposals put forward by Appleton's boss, the head of OIOS Inga Britt Ahlenius, the Task Force would be merged into a reformed Investigations Division.
Panorama: Mission Impossible will be on BBC One at 8.30pm on Monday 28 April 2008.