Bernard J. Ebbers, a former CEO for WorldCom, may face serious charges as the chief witness in the court Scott Sullivan said his ex-boss was involved in a costly $11 billion financial fraud in the company.

Mr. Sullivan, once being a finance chief for the company, pleaded guilty to financial fraud and said his colleague and friend was directly involved in the fraud. Last year he agreed to help government in the investigation. "He has got a hands-on grasp of financial information," said Mr. Sullivan in his testimony.

The point is that Mr. Ebbers knew much more about the accounting in the company than the rest of financial officers, said Mr. Sullivan. In spite of this, defense team for Ebbers claims their client was unfamiliar with detailed accounting practices in the company.

Ebbers denied all the charges and said he was “unaware of fraud.”

If convicted of all charges, Mr. Ebbers may face up to 85-year sentence.