How corruption works: Kenya
The scourge of corruption is showing no signs of slowing, according to a report by the campaign group Transparency International.
In Kenya, the issue of university teachers asking female students for sexual favours in return for better grades has hit the headlines in recent months.
One student - who asked to remain anonymous - tells of her experience. Her words are spoken by an actor.
There will be a series of special reports and articles this week as the BBC examines why bribes and backhanders are part of the system in so much of the world.
- From the section Business