1) Call records of bank manager
2) Call records of chartered accountants
3) Entries in farmers accounts
4) Entries in shell companies which had cash on books
5) Last minute travel that was ticketed and took place between Nov 9-16
6) Bank Accounts with unusual activity as a percent of previous years average.
Everybody give ur crisp best ideas. The real Swachh Bharat is in sight now..Yeh chal gaya to dooosra to chal hee jaayega more