The Sunday Life breached the Editors' Code of Practice by publishing a letter sent by a rape victim to her attacker.
The Press Complaints Commission found the paper breached clause three (privacy) and contributed to her identification as a victim of sexual assault in breach of Clause 11 (victims of sexual assault) of the code.
The complainant was a victim of Jason King, who was convicted of 58 offences including nine rapes involving girls between the ages of 12 and 15.
In his original trial the complainant's diary was used as evidence, but years later she wrote to him saying she 'didn't want [him] to go to jail", would "never forgive" herself for her role in his conviction, and had considered saying that her diary was a "lie". She also asked to visit him in prison.
The Sunday Life obtained a copy of the handwritten letter and showed it to her mother for comment before publishing it. The PCC said the paper obscured only her name and address.
The complainant said the newspaper had 'failed to respect her private life'because how she felt about King and what she had written to him were private matters.
She also said she had 'undergone lengthy therapy, and the newspaper should have been aware of the article's potential to cause further harm", and felt the story contained enough information – including her current age, her age at the time of the attack, and a sample of her handwriting – to identify her as a victim of sexual assault.
In its defence, the Sunday Life said that while it 'greatly regretted the distress caused to the complainant, it considered that the letter indicated that she was still â€˜infatuated' by a man who had manipulated her as a schoolgirl.
'The coverage had highlighted how Mr King continued to have a psychological hold over his victims, which was a matter of overwhelming public interest."
It also denied claims it was 'intrusive'to show the letter to her mother before publication.
Outlining the paper's defence, today's PCC adjudication said: 'She had already been aware of Mr King's crimes and had made strenuous efforts to stop her daughter contacting him; she was "the one person who absolutely needed to know" about the letter.
'It [Sunday Life] said that the letter would have become public knowledge in any case, because Mr King had been "bragging" about it.
'It had been suggested to the newspaper that he intended to use the letter to launch an appeal, although the newspaper had concluded that this was unlikely."
The PCC said it was an 'unusual complaint'because the complainant had not been named and 'would not be identifiable to the vast majority of the newspaper's readers".
But it concluded the complainant's feelings toward King were 'extremely intimate matters, so much so that the existence of the correspondence was unknown even to her family".
'Regardless of whether she was identifiable, she retained a right to privacy with respect to such correspondence,'according to the PCC.
'The question was whether a countervailing public interest justified publication. There was an undeniable public interest in exploring the deep and lasting effects of sexual abuse, which the complainant's letter illuminated vividly.
'Balanced against this was her extreme vulnerability: she had been the child victim of extremely serious sexual offences and suffered ongoing trauma as a result.
'The reproduction of the letter and the public exposure of the complainant's private feelings had evidently caused severe distress. In the Commission's view, the newspaper could have achieved its aim - to expose the extent of Mr King's continuing hold on one of his victims - through less intrusive means.
'It concluded that the reproduction of the handwritten letter, in full, represented an unjustified intrusion into the complainant's private life without consent in breach of Clause 3."
The commission also concluded that the decision to show the letter to the complainant's mother without her consent represented a further breach of clause three.
Clause 11 was also breached because the article had included the complainant's current age, her age at the time of the attack, the general area in which she lives and an image of the letter, 'which showed her distinctive handwriting".
'Again, it was the publication of the letter that tipped the balance,'said the PCC.
Complaints under clauses one (accuracy) and four (harassment) were not upheld.