Media playback is unsupported on your device Media caption Nick Smith says his warnings about his ex-partner were ignored

Families of children who die as a result of neglect or abuse should be able to challenge review findings, Wales' Children's Commissioner said.

Child practice reviews investigate the role of statutory agencies in such cases and look at lessons which may be learnt to prevent future tragedies.

But Sally Holland said families can feel sidelined by the review process.

The Welsh Government said the views of families were of "great importance" and extra training will be put in place.

Child practice reviews are carried out by multi-agency boards, but Ms Holland said she was concerned these boards were unaccountable to any higher body and also that families of a deceased or injured child cannot contest the review findings or have any input in the wording of the final report and its recommendations.

Nick Smith, whose toddler son Izaak was killed by his former partner, contacted the Children's Commissioner's office in 2013 after trying unsuccessfully to challenge the findings of a multi-agency review into the case.

Melanie Stevens, a mother of five, suffocated two-year-old Izaak and his half-brother Phillip, five, at their home in Trawsfynydd, Gwynedd just before Christmas in December 2010 before hanging herself.

The 36-year-old had been embroiled in custody proceedings at the time.

Image copyright Family picture Image caption Mother-of five Melanie Stevens killed two of her children in 2010 before hanging herself

An inquest in September 2011 recorded verdicts of suicide for Ms Stevens and unlawful killing for Phillip - known as Pip - and Izaak.

Ms Stevens, who was pregnant at the time, killed the children and herself on the day Mr Smith was due to collect Izaak for his first overnight stay with him.

A serious case review, carried out by Gwynedd and Anglesey local safeguarding children board and published in October 2011, concluded little could have been done to save the children's lives.

Various agencies including social services, health services, the local education authority and child guardian body Cafcass Cymru, had been involved with the family over a number of years.

The review found "arguably" the only way to have saved the children would have been to remove them from their mother, but there were no grounds to do so.

However Mr Smith, who has two adult children from a previous relationship, believes that more could and should have been done.

Mr Smith, of Llanllyfni, near Caernarfon, said: "I believe that the conclusion of the serious case review, that this couldn't have been predicted, is inaccurate considering I spent the previous 18 months telling these professionals that this could happen.

"I felt that Izaak and Pip were dead and that the record of their lives was incomplete and not of great value bearing in mind that the only formal record of their lives really was the executive summary of the serious case review.

"I was angry that I couldn't get anywhere, that people in positions wouldn't listen to me. I was angry, frustrated, deeply upset at the whole process."

Image copyright Family picture Image caption A review found little could have been done to save Izaak and Phillip

Mr Smith had asked for a mental health assessment to be carried out on Ms Stevens - who had made previous threats to harm herself and her children.

He also urged social services to hold a 'children in need' conference for the family.

Neither request was acted upon.

The review report acknowledged that Mr Smith felt his concerns had not been taken seriously enough.

It highlighted several lessons to be learned from the case and put forward ten separate recommendations to improve the way agencies work together.

Alun Ffred Jones, former AM for Arfon, was contacted by Mr Smith during the review.

"I contacted the minister at the time and asked her to intervene, and she said she couldn't," Mr Jones said.

"I've every sympathy for officers involved in cases like this, these are difficult cases… but I thought that it seemed that natural justice wasn't seen to be done here.

"It seemed to me that he had a serious case that the process should be more open, he should be able to challenge aspects of it and comment on it to his own satisfaction.

"He's a man grieving… he has an acute sense of loss, and it seemed as if the processes were saying 'no, that's it, thank you very much, go away'."

Although serious case reviews were replaced by child practice reviews in 2013, the legislation governing them does not allow any recourse for families or others to challenge their findings.

Ms Holland has written to Wales' children's secretary Carl Sargeant, about her concerns in the hope that the Welsh Government will change some of its procedures.

The Welsh Government said: "The views of families are of great importance in the consideration of lessons to be learned from any case.

"Work is ongoing with regional safeguarding boards to develop additional training on child practice reviews."

According to Welsh Government guidance, all safeguarding boards should have a complaints procedure in place.