The numbers are staggering. First came the more than $2bn (£1.3bn) allegedly siphoned off by Nigeria's senior military officers in arms procurement deals.

Now the state oil company is accused of failing to hand over $16bn to the treasury in 2014 alone.
Add in the millions of dollars of monthly salary which went to so-called ghost workers, and other apparent discrepancies, and the total comes to almost $19bn.

Legal cases continue, and identifying gaps is not the same as recovering money.
It's clear though that President Muhammadu Buhari has made fighting corruption a priority. But defeating such a deeply ingrained practice will be a very difficult task.