This Indian blogger has, not surprisingly, had some past interest in the actions of Dr Khan, or as he likes to refer to him, the Centrifugist.
See, for example, this February 18, 2007 entry.
That referenced the November/December 2006 issue of the Bulletin of Atomic Scientists, which had two articles worth reading on the Khan network. They were ‘Where Is The Justice?’ and ‘The Unmaking of A Nuclear Smuggler’, by the indefatigable Mark Hibbs.
Other interesting Centrifugist entries, to name just a few, are here, and here. Better yet, just search online for The Centrifugist.
Google just gave 538 hits for that.