An undercover federal agent testified Wednesday in the racketeering and fraud trial of former New Roads Mayor Tommy Nelson that Nelson began accepting cash bribes in 2009 after being warned that stock payments risked exposure.

FBI Special Agent Mike McKinney testified in federal court that he posed as a corrupt executive of a garbage can-cleaning business when he met Nelson in April 2009.

McKinney said another undercover FBI agent and a paid undercover operative already had promised Nelson $20,000 in the stock of an electronic medical records company by the time he talked with the mayor.

McKinney told Assistant U.S. Attorney M. Patricia Jones that the stock was payment for Nelson’s help in obtaining municipal business for the can-cleaning company, Cipher 5000.

Cipher 5000 actually was a fictitious company used in an FBI sting operation.

McKinney said he told Nelson payment in stock was too risky because it would leave a paper trail.

“It is illegal for him (Nelson) to be doing what he was doing on behalf of Cipher,” McKinney testified.

“I told him that cash was better than a stock deal,” McKinney added. “The offer was $10,000 now ... and then another $10,000 once the Cipher trucks hit the ground.”

McKinney later added: “I paid him $5,000 on Sept. 24 (2009) ... and $5,000 in October.”