RALEIGH, N.C. — After fighting one of the nation’s largest corporate fraud cases, former Adelphia Communications executives John and Timothy Rigas reported Monday to a federal prison in North Carolina.

Adelphia founder John Rigas and his son Tim, the company’s former chief financial officer, were convicted in 2004 on multiple charges of securities fraud, conspiracy to commit bank fraud and bank fraud, but had remained free while their appeals navigated the courts system.

In June, Federal District Judge Leonard Sand recinded the order allowing them to remain free, giving the father and son until Aug. 13 to report to prison. John Rigas, 82, was sentenced to 15 years and Timothy Rigas, 51, to 20 years for their role in the collapse of one of the nation’s largest cable television companies.

The pair had asked that they be allowed to serve their time together at a facility close to their homes in Coudersport, Pa. Instead, the federal Bureau of

Prisons sent them to the Butner Federal Correctional Complex, located about 45 minutes northwest of Raleigh.

They were registered at 10:35 a.m. Monday at the complex’s low-security prison, said Mike Truman, a federal prisons spokesman in Washington.

Prosecutors claimed the Rigases made Adelphia’s finances appear more robust when they were in fact dangerously overextended by concealing nearly $2.3 billion of the company’s debt.

They also accused the family of using company funds to finance personal follies, including 100 pairs of slippers for Timothy Rigas and more than $3 million to product a film by John Rigas’ daughter.

Another of John Rigas’ sons, Michael Rigas, also received 10 months of home confinement after pleading guilty to making a false entry in a company record.

The Butner Federal Correctional Complex is home to a low-security prison, two medium-security facilities and a medical center for male inmates. Among the inmates at Butner are Israeli spy Jonathan Pollard and former North Carolina Democratic Rep. Frank Ballance.

Sami al-Arian, a Palestinian who taught computer science at the University of South Florida and admitted in a plea bargain to conspiring to aid Palestinian Islamic Jihad, was held at the medical prison earlier this year while he conducted a hunger strike for more than two months.The elder Rigas has a history of health problems, including bladder cancer.

Authorities began investigating the company in 2002 after the company announced its 2001 results with a press release that included a footnote on its final page noting Adelphia had billions in liabilities not previously reported on its balance sheet.

Even after their convictions, the Rigases were not sentenced for nearly a year while the men wrangled with prosecutors about restitution for Adelphia stockholders.

The pair still hope an appeals court might grant them a new trial, based in part on an argument that the star witness against them, Adelphia’s former vice president of finance, James Brown, gave differing accounts of the alleged fraud in civil and criminal court proceedings. The two also hope the U.S. Supreme Court will hear an appeal.