NEW YORK (CNN/Money) - After former Enron CEO Jeffrey Skilling pleaded not guilty to charges of fraud and insider trading Thursday, his lawyers and government prosecutors started arguing their cases in front of the news media.

Following are comments from both sides in the case.

Ex-Enron CEO Jeffrey Skilling surrenders to the FBI in Houston Thursday.

Daniel Petrocelli, Skilling's lawyer, accused the government of making his client a "scapegoat," adding Skilling had done "nothing wrong."

Speaking to reporters outside the federal courthouse after his client pleaded not guilty to 36 charges, Petrocelli said Skilling had chosen to take a lie detector test when the Enron scandal broke two years ago "and passed it with flying colors." He said the test was administered by a polygraph expert respected by the FBI.

Skilling was charged with insider trading, wire fraud, securities fraud, conspiracy and making false statements.

""He did not steal, he did not lie, he did not take anyone's money," Petrocelli said.

"They, backed by the resources of the federal government and an army of lawyers and investigators," he continued, "have spent over two and a half years and untold millions of dollars, digging through tens of millions of documents and talking to everyone under the sun looking for that kind of evidence.

"And it doesn't exist because Jeff Skilling did nothing wrong."

Petrocelli said "nobody feels worse" than Skilling about Enron's downfall.

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He said he told prosecutors "they were making a grave mistake in pursuing Jeff Skilling, but they have decided to turn a blind eye to all of it. I guess they need a scapegoat. I guess Jeff Skilling is their scapegoat."

He said Skilling will prove his innocence in court.

Meanwhile, in Washington, top federal law enforcement officials issued a joint written statement lauding their actions.

"This indictment marks an important milestone in the life of the president's Corporate Fraud Task Force," said Deputy Attorney General James Comey, who heads the unit.

"Our investigators were able to cut through the maze of paperwork and financial trickery to get to the bottom of the scheme and charge Skilling, once the top executive at Enron, with fraud and other crimes that contributed to Enron's collapse," he added.

The assistant attorney general who oversees the Criminal Division, Christopher Wray, echoed the view.

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"The indictment of Enron's CEO shows that we will follow the evidence wherever it leads -- even to the top of the corporate ladder," Wray said.

FBI Director Robert Mueller joined with the Justice Department leaders in hailing the indictment.

"The Enron Task Force's probe and today's indictment represent both a substantial step for justice and strong continued action on the part of the FBI's Corporate Fraud Initiative," Mueller said.

The three officials, along with SEC Enforcement Chief Steve Cutler, have scheduled a news conference at the Justice Department to detail the allegations against Skilling. (Click here for more on the indictment.)