The Daily Mail and Daily Mirror have each been fined £10,000 for contempt of court over articles published after a killer's conviction for the abduction and murder of schoolgirl Milly Dowler.
The fines were imposed by two judges at the High Court in London in a case brought against them by Attorney General Dominic Grieve.
Both papers, who contested the action, had been accused of publishing "seriously prejudicial" articles.
At a hearing in June, Sir John Thomas and Mr Justice Tugendhat were told that stories in the two publications were part of an "avalanche" of adverse publicity which followed the guilty verdicts against Levi Bellfield - while jurors were still deliberating another charge against him.
They were told that as a result of the "totality" of the publicity, the Old Bailey jury was discharged from returning a verdict on that count.
The charge alleged that the day before Bellfield snatched Milly from a street in Walton-on-Thames, Surrey, in 2002, he attempted to abduct Rachel Cowles, then aged 11.
Bellfield, who was previously convicted in 2008 of the murders of Marsha McDonnell and Amelie Delagrange and the attempted murder of Kate Sheedy, was found guilty on June 23 last year of Milly's murder.
The newspapers argued that their publications would not have created a substantial risk of serious prejudice.
But the two judges ruled in favour of the Attorney General, who brought the action against Associated Newspapers, publisher of the Daily Mail, and MGN, publisher of the Daily Mirror.
Following a further hearing in the case, the judges ruled that the penalty for each would be £10,000.
Announcing the penalties to be imposed, Sir John said: "In considering the respective aggravating and mitigating factors we have also taken into account that both parties have agreed to contribute the sum of £25,000 each to the costs of the Attorney General, meeting significantly the public costs of bringing these proceedings."
He said it was clear that "both newspapers went further than what was permitted" in what was published.
The judge added: "We have little doubt that they should have appreciated the risk under the strict liability rule at the particularly sensitive point in time at which the decision was made to publish.
"However, we can conclude that this was a case where there was an error of judgment through a failure to properly analyse the articles - an analysis which was nonetheless essential at that point in time."
Sir John said: "This case is therefore important to the media in pointing out the necessity of very careful analysis of material that is to be published as part of a background, when one verdict (or more than one) has been delivered but others are outstanding.
"There is a particular need for caution at that time because the risks can be so great.
"It is therefore a very important mitigating feature that the court would add in this case that the importance of that careful and detailed analysis may not have been present to the minds of those who made the decision.
"However, after this case, that can no longer be seen as an excuse."
Sir John said: "We should also add that we appreciate the probability that each publication will write to the family concerned apologising for what happened.
"That is important because ultimately the real victims in this case have been the family of Rachel Cowles and Rachel herself, in that they feel they have not had justice.
"Bearing in mind the amount of costs paid, we can take the course in this case of fining each newspaper at the very bottom end of the scale, namely £10,000 each.
"But for the future the message is clear and the court's observations, we hope, will ensure others exercise the most scrupulous care at the critical time in a case where only some verdicts have been returned and others remain outstanding."