A contingent of Pakistani peacekeepers was accused of selling gold and guns between 2005 and 2006 to Congolese militia groups they were meant to disarm.
The investigation, which began in early 2006, found no evidence of gun-running.
Pakistani officials have previously denied all the accusations, describing the allegations as "baseless".
In May the UN said it would seek to discipline anyone who had compromised peacekeeping in DR Congo by trafficking in gold or guns.