The "professional arrogance" and paternalistic attitude of doctors who removed hundreds of organs from dead children without parental knowledge or consent led to a "social and ethical time bomb waiting to go off", an inquiry report said today.

The report into the removal of hearts from children at Bristol Royal Infirmary called for a strict new code of practice to be introduced regulating the removal and retention of organs and the treatment of bereaved parents.

The interim report, produced by the Bristol Royal Infirmary inquiry, includes almost 70 recommendations covering coroners' inquests and post mortem examinations carried out by hospitals.

Its authors criticise the way in which doctors routinely took human material from dead children for a variety of purposes and kept large collections without the knowledge of parents or the public.

The hearts of 170 children at the Bristol hospital were removed during post mortem examinations and kept for educational purposes without parents' knowledge, causing great distress to those parents when they later learned that they had buried their children with organs missing.

The scandal emerged during investigations into high death rates of children who underwent heart surgery at the Bristol hospital between 1984 and 1995.

The inquiry into heart surgery at the hospital, which is being led by Professor Ian Kennedy, was widened to include the way organ removal was handled and today's report focuses on this issue.

The report found that during the inquiry's terms of reference and indeed for some time after "there was in essence, a professional arrogance, justified when necessary by the recourse to traditional paternalism, that parents, on this view, are best kept from the details but would be thankful if they knew what was being done".

It added: "Fundamentally, there was a social and ethical time bomb waiting to go off. It is no surprise that the explosion of anger, when it came, was huge."

The report said the cause lay in two conflicting attitudes, which were the parents of a recently deceased child continuing to regard the organs as part of the child's body and therefore still the child, and the pathologists and clinicians for whom such material was simply a dehumanised specimen.

The study called for a strict code of practice to be introduced to help solve this conflict which would be based on two fundamental guiding principles: first and foremost, respect for parents and their dead child; second, the value of continued access to human material for the advancement of medical care and treatment.

It recommended parents should be told exactly what was going on and what the benefits would be from organ removal, as well as making sure that parents were told in an appropriate manner and at a suitable time.

Evidence within the report showed that parents found themselves asked to discuss the signing of papers at a time which was too close to the death of their child, when they were "clearly and understandably unable to comprehend what was being put to them".

The report recommended: "Obtaining parents' consent should be seen as a process, and not just a signing of a form. As part of that process parents should be allowed proper time to reflect and be informed that they may change their mind until such time as they sign a form indicating their consent."

It was also recommended that parents should be told that they may refuse consent for the retention of organs and be able to do so in a supportive atmosphere where they had access to clear and comprehensible information.

The report branded the law regulating the removal, retention, use and disposal of human material as "obscure, uncertain and arcane" and recommended that it should be amended or clarified.

It recommended that the code of practice, backed with appropriate enforcement mechanisms for example, incorporating it into the employment contract of clinicians should be backed by the Government.