Former Enron CEO Jeffrey Skilling has been released from federal custody after spending 12 years in prison for his role in masterminding one of the most notorious corporate frauds in history, the US Bureau of Prisons has said.

Skilling, 65, was released on Thursday after serving 12 years in prison and six months in a halfway house after being convicted for actions that led to one of the worst corporate meltdowns in history. He was convicted of 19 counts of conspiracy, securities fraud, insider trading and lying to auditors in connection with the collapse of the Houston-based energy giant.

The company collapsed into bankruptcy in 2001 under the weight of years of illicit business deals and accounting tricks. Skilling was sentenced to 24 years in prison, but was able to walk free sooner due to a reduced sentence.

In August, Skilling was released to a halfway house at an undisclosed location from a minimum security federal prison camp in Alabama. Skilling was the highest-ranking executive to be punished for Enron’s downfall.