Actually, Niger is a producer of uranium ore. A French company runs the mines and Niger gets a royalty. There was no record of sales to Iraq because there was a smuggling operation moving some of the yellowcake to Libya, who then sold it to Iraq (among others).
The yellowcake found stored in Iraqi warehouses actually did come from Niger -- as British intelligence had stated. Uranium ore has a unique isotopic signature, depending on where it comes from.
Thank you for the correction and clarification. Truth rules!