Nairobi, June 28 -- In March 2011, then-Democratic Republic of Congo president Joseph Kabila flew into the country for emergency talks with his host Mwai Kibaki on a rather unusual subject - theft of a large consignment of gold.

The previous month, the murder of a Kenya Revenue Authority (KRA) official, which within security circles had been linked to a gold syndicate, had given a sneak peek into the high-stakes criminal business.

However, it was the unannounced visit by the Congolese president that would expose the extent of the illegal trade, and in particular, the consignment that had caught the attention of the leader of the mineral-rich country that has been plagued by civil war.

Reported to weigh 2.5 tonnes, the gold was estimate...