The Daily Mirror was today fined £50,000 and The Sun £18,000 for contempt of court over publication of articles following the arrest of a suspect by police investigating the killing of landscape architect Joanna Yeates.
Three judges at the High Court handed out the penalties to the publishers of the two tabloid newspapers.
The Lord Chief Justice, Lord Judge, sitting in London with Lord Justice Thomas and Mr Justice Owen, ruled that the newspapers breached contempt laws in reports about Miss Yeates's landlord, Christopher Jefferies.
Attorney General Dominic Grieve, who brought contempt proceedings and told the judges that reports would have posed a "substantial risk" of prejudicing any trial Mr Jefferies might have faced, described the court's decision as an "extremely satisfactory outcome".
Both newspapers had disputed Mr Grieve's allegations and denied contempt.
After the hearing, Mr Grieve said the two newspapers "lost the plot".
"It was an extraordinary case," Mr Grieve told journalists.
"When Mr Jefferies was arrested these two newspapers completely lost the plot.
"They just went on this extraordinary frolic - vilifying Mr Jefferies in a way that was, frankly, outrageous.
"By doing this they made any possibility of a successful prosecution very much more difficult.
"I have rarely seen a level of vilification to an individual of this type."
Mr Grieve said he was "very pleased" with the outcome and added: "I thought these were flagrant contempts."
He said the level of fine was not as important as the "message" sent out by judges.
"Historically, fines for contempt have never been particularly high," he added. "The message is much more important than the level of the fines."