Almost two years after the scandal broke that brought down Enron and it's accounting firm Arthur Andersen, the first executive from Enron has been sent to prison for his role in the failure of the energy giant.

Ben Glisan, former Enron Treasurer, was sentenced to five years in a federal minimum-security prison camp in Texas after pleading guilty to one count of conspiracy. He immediately started serving his sentence, which includes three years probation, because he was not cooperating further with investigators in the ongoing case.

Glisan admitted to having "engaged in a conspiracy to manipulate artificially Enron's financial statements."

Glisan was originally named in a 109-count indictment, along with CFO Andrew Fastow and finance executive Dan Boyle. Both Boyle and Fastow have pled not guilty to the charges against them, and are awaiting trial.

As part of his plea agreement, all additional charges against Glisan were dropped. Additionally, he agreed to forfeit the $1 million gain he realized on one of the fraudulent "special purpose entities" he was involved in, and will not seek a refund of the $412,000 he paid in income taxed on that profit.

The director of the Justice Department's Enron Task Force views Glisan's admission of guilt as a very positive development. "I think there is a lot of value in someone standing up and admitting that there was significant financial fraud at Enron," Leslie Caldwell said. "Certainly, it sends a good message to others."