The founder of cable-TV firm Adelphia Communications, John Rigas, has pleaded not guilty to fraud charges.

Mr Rigas, together with two of his sons who were also Adelphia executives, entered not guilty pleas to charges of conspiracy, securities, wire and bank fraud.

Two other former Adelphia executives, James Brown and Michael Mulcahey, also pleaded not guilty.

Prosecutors allege that executives were involved in a scheme to defraud investors by exaggerating results.

They also claim that members of the Rigas family made improper use of company funds.

Loans

In March this year, Adelphia admitted having guaranteed �2.3bn in loans to the Rigas family, which then controlled the company.

Questions about financial transactions between the firm and the family led all Rigas family members to resign from the company board in May.

John Rigas founded the company and was serving as chairman and chief executive.

One of his sons, Timothy Rigas served as chief financial officer, while another son Michael was vice-president of operations.

In June, Adelphia filed for bankruptcy after it defaulted on $7bn of bank loans.

Investors 'misled'

At the time of Mr Rigas' arrest in July prosecutors said the actions of former Adelphia officials had resulted in massive losses for investors.

They also alleged that members of the Rigas family had stolen "hundreds of millions of dollars" from the firm.

The Department of Justice also alleged that the defendants intentionally gave false information to lenders and made false statements to the public in order to protect Adelphia's share price.

The government is seeking to reclaim $2.5bn in what they allege is illegal proceeds.