In a graft case last year, a forklift operator collected bribes of between 10 cents and $1 from truck drivers to let them jump ahead of others to pick up or drop off containers.
Such petty corruption is tackled just as severely as cases involving large amounts of money, said a senior officer from the Corrupt Practices Investigation Bureau (CPIB).
For the first time, officers from the agency spoke about some of their major cases in an exclusive interview.
One such case involved a Singaporean who traded confidential US Navy documents for cash and luxury hotel stays.
Gursharan Kaur Sharon Rachael eventually owned up after hours of intensive interrogation to giving sensitive information to Malaysian businessman Leonard Glenn Francis, the ring leader in a massive bribery scandal.