The Rigas family -- former controlling clan of US cable operator Adelphia -- have been handed an unexpected boost in their defense against fraud charges after the judge ruled that prosecutors had made "an egregious error".

John Rigas (the company's founder), his sons Michael and Timothy, and former Adelphia executive Michael Mulcahey are accused of looting the firm of billions of dollars.

However, the prosecution hit an early setback when its first major witness, former Adelphia director Dennis Coyle, admitted his earlier testimony was based on a misunderstanding of loans to the Rigases.

Judge Leonard Sand said the error could be grounds for a motion for a mistrial. However, the defense is expected not to take this option; instead, it is likely to ask the judge to dismiss the gravest charge against the Rigases: bank fraud.

Data sourced from: The Wall Street Journal Online; additional content by WARC staff