Jake Wallis Simons explores the murky and controversial world of private investigators.
BBC Radio 4
2/5 Roger continues his journey through Shanghai, visiting a bank museum and a tobacco museum.
Christopher Gabbitas explores the effects on singers of changing the pitch of their voice.
Can we use the Amazon for the wealth of resources it contains, but still keep it alive?
2/3 Iran is subsumed into Arab Muslim, Turkic and Mongol empires, but fight their conquerors.
3/6 Debating the advantages and disadvantages of being really huge, or extremely small.
Richard Coles on the various ways that the voice of God is depicted, and what this reveals
1/5 Roger begins his tour of Chinese museums in Shanghai, with a visit to an opera museum.
Sustainability at the Olympics, Rio +20 reaction, and Jamaican herbs.
BBC World Service
Robert Elms reflects on music from Noel Coward, Lily Allen, The Clash and The Kinks.