CORRUPTION..
It can only be stopped by stopping it at it's starting point.
These two steps can be applied at the present Nigerian situation.
Step-1.
The financial reports of ALL the MDAs and parastatals and political offices (no exceptions) from last 10years or 20years should be submitted and seriously audited by independent auditing firms. (Lots of dubious diversions and transactions would be sniffed out, and the affected officers should be prosecuted without fear nor favour nor selective justice)
Step-2.
Monthly financial and activity reports from the MDAs and parastatals and political offices, also to be seriously audited by independent auditing firms., which would still be rechecked if necessary.
..
In other words, with continued and continuous checks on the movement of funds, any diversion or mismanagement would be immediately be sniffed out, and the officers involved severely (appropriately) punished.
...
With good checking/control systems in use, corruption would be maximally reduced.

Question:

Had these suggestions not been practiced in Nigeria all these while?

tk4rd:
Question:

Had these suggestions not been practiced in Nigeria all these while?

Answer:

What we always see in Nigeria is selected auditing. Not all MDAs and parastatals and political offices are audited.
And when loopholes are found, the said auditing firms are the ones to help cover up the glaring evidence of diversions.
And even when unavoidable loopholes are found in the reports, there would always be selected punishment to some scapegoat officers.
Even the quarterly reports from the MDAs and Parastatals are shabby, non-detailed, filled with assumed quantities, and manipulated figures.. And yet, the engaged independent auditing firms would allow the reports to be accepted as authentic, and allow the manipulated sections to pass as "classified" sections.