Maureen Nzioki is a private investigator based in Nairobi in Kenya, a country where this industry is well established. She says she never feels guilty for trailing a suspected cheating spouse, because she is only following instructions from their husband or wife, whose trust they have broken. Although Maureen loves her job, it has made her cynical about relationships, and she now finds it hard to trust any potential partner.

Akriti Khatri runs her own private detective firm in Delhi, and after a decade in the business puts her success down to a combination of confidence, chattiness and patience. Critics say agencies like Akriti's are unregulated, employ illegal surveillance techniques and routinely invade people's privacy, but she says she is providing a useful service, preventing bad marriages from ever taking place, and catching cheats in love and business.

(Picture: Private Detectives Maureen Nzioki [Left] and Akriti Khatri [Right])