As our van rolled to a stop in front of the Rantau Panjang security checkpoint near the Malaysian-Thai border, an officer from the General Operations Force (GOF) walked out of the guard post and motioned us to lower the window.

"Sepuluh ringgit, cepat, cepat (RM10/S$2, hurry, hurry)," he whispered, extending his hand inside the vehicle and glancing nervously at the other vehicles that had pulled up behind our dilapidated van.

An undercover enforcement officer in the front passenger seat pulled out RM10 and handed it to the middle-aged GOF officer. He then let us through with a wave of his hand.

Moments later, at another checkpoint - this time, Customs - the undercover agent got out and opened the back door of the van and showed them our illicit cargo of contraband fragrant rice stuffed in pillowcases and other taxable goods.

The payoff this time was RM50 (S$20.50) and the methodology involved a bit of sleight-of-hand.