To glance at some headlines, a reader might think this was a conventional love story: "I still love him"; "He's wonderful, I'll fight for him". But this was, child protection professionals agree, a relationship built around abuse.

Jeremy Forrest, a maths teacher who turns 31 on Tuesday, was jailed for five and a half years last week for beginning a sexual relationship with a pupil shortly after her 15th birthday and escaping to France with the girl when their connection was discovered.

Post-verdict coverage has shone a spotlight on the many ethical and regulatory difficulties of such cases. While newspapers have remained condemnatory of Forrest himself, interviews with the girl, now 16, and with Forrest's family, traced a distinctly romantic narrative, with talk of her visiting her ex-teacher in prison, sticking by him and even future marriage.

Beyond the unequal basis of their relationship, the court heard that the girl, who cannot be named for legal reasons, is psychologically vulnerable and from a difficult background. Her decision to side with Forrest and his family has seen her cut contact altogether with her own mother.

Stories, primarily in the Sun and Mail titles, detailing her feelings for Forrest, including reprints of emotionally charged letters, were "a concern", said Jon Brown, who leads on child protection issues for the NSPCC charity. "There's an awful lot of work that still needs to be done with the media in explaining and, in a sense, educating journalists so they do have a better understanding of the reality of these relationships," he said.

"In terms of the impact on the young person, there are many parallels between a case like this and sexual abuse involving a younger child. The conceptualising of it as a kind of love affair provokes a lot of public interest, and I'm sure sells more papers. But fundamentally, that's not what it's about – that implies a much greater level of equality in the relationship, and of course that wasn't the case with a relationship where someone's in a position of trust, like a teacher."

Newspapers running such stories must also beware of a series of clauses within the Press Complaints Commission code of practice, still in force as efforts to create a new regulator inch ahead.

One issue centres around whether the papers concerned paid for stories. Clause six of the PCC code prohibits payment "for material involving children's welfare", and was invoked in 2009 when several tabloids covered the case of a baby born to a 15-year-old where the father was believed to be an even younger boy, aged 13. The one story in which the girl involved in the Forrest case is quoted does, however, stress that she was not paid.

Also potentially relevant to such stories is clause 16, which precludes payment to criminals or their "associates", which can include family members. Earlier this year Real Life magazine was chastised by the PCC for paying the sister of a murderer for her story, dismissing the argument that she also counted as a victim.

Finally, clause nine warns about "the potentially vulnerable position of children who witness, or are victims of, crime".

There is some leeway in the Forrest case in that the broad facts – that the pair had a sexual relationship and remain close – were aired in open court. Also, all these clauses can be circumvented if there is a legitimate public interest defence argument. This must be robust and well-argued, particularly when it comes to stories involving minors, said a source familiar with the workings of the PCC, who asked not to be named.

"The overarching role of the code, which will continue with the new regulator, is to specifically protect the interests of the child," the source said. "By not naming her [the girl in the Forrest case], this gives them more freedom.

"But then there's an ethical issue which is broader than the code: are papers talking about this in a responsible way? And this is something where it's good for newspapers to be challenged, for example by child protection people."

Such child protection issues should be made clear in cases such as that of Forrest, argued Dr Michael Hymans, an educational psychologist: "The crucial thing here is that this took place in a setting in which the adult was in a position of power. He carried all the trump cards."

The fact that the girl gave evidence in court in support of Forrest did not diminish this point, he added: "We don't know the conversations between them. What happens in an abusive relationship is that the abuser will make threats about what might happen if the child tells: 'If you say anything it could split up your family.'

"It's like emotional blackmail. He may have asked her to wait for him, planted some of those seeds emotionally, maybe not even consciously."