A sixth person faces federal criminal charges related to a fraud scheme at the defunct Adams Produce Co., Birmingham, Ala.

John Alexander, former chief financial officer, is free on a $5,000 bond after being arrested May 15 in connection with a 33-count criminal indictment by a federal grand jury. The charges against him include wire fraud and conspiracy.

Alexander’s attorney said he pleaded not guilty and actually helped officials build the case against the company.

“Contrary to these allegations, Mr. Alexander was in effect a whistle-blower and has cooperated fully with this investigation,” said Augusta Dowd in a May 15 statement.

Five other Adams Produce officials pleaded guilty to charges related to the fraud scheme involving overcharging the federal government for fresh produce for the military and public schools.

Four of those officials, including chief executive officer Scott Grinstead, have been sentenced to prison. The fifth was sentenced to probation. Four of the executives have been ordered to jointly repay $481,000 in restitution.

According to the indictment, Alexander exchanged e-mails with the other executives about the scheme, including messages discussing what to name a fake company that was set up to track fraudulent transactions. Former executive Michael O’Brien suggested the names DSF, short for Dave’s Slush Fund and GBM, short for Guaranteed Bonus Maker, in the e-mail messages, according to the indictment.

The scheme was in place from August through November 2011, according to court documents and plea agreements signed by the executives. The company filed for bankruptcy in 2012.

Grinstead along with other executives and a private equity firm bought the company in 2010 from the Adams family. Edwin Adams founded the produce company in 1903.