How a lie detector test works
An increasing number of companies in India are offering lie-detector tests to individuals and companies trying to catch out deceitful spouses and cheating employees.
One such company, Helik Advisory, which has been operating for a year, says it is getting more enquiries about its polygraph tests every day.
Using a number of sensors attached to the body, physiological changes can be used to determine whether someone is telling the truth.
A major change in any pattern, also known as a "response conflict", is a sign a person is lying.
Polygraph tester Deepti Puranaik put the BBC's Rajini Vaidyanathan through a lie detector to show her how the technology works.
12 Sep 2012