There has been a fall in the numbers of people willing to donate human tissue for medical research following a string of organ retention scandals in recent years, researchers claimed today.

The high-profile cases at Alder Hey children's hospital in Liverpool and the Bristol royal infirmary, where thousands of organs were taken from youngsters and kept without the parents' knowledge, have prompted qualms among potential donors.

This week more than 2,000 families who had experienced similar treatment at other hospitals took their cases for higher compensation to the high court.

Researchers writing in the Journal of Clinical Pathology said the negative publicity surrounding organ retention was a possible reason for an apparent shift in opinion and willingness to allow tissue to be used for research.

A team from the University of Newcastle conducted a small study involving the attitudes of 100 people at an NHS dental practice in northern England.

They found that almost one in five (18%) said they would refuse to give consent for any of their tissue - such as from the brain, lungs, bone and heart - to be used for medical research.

Of those who would donate tissue, the most popular choice was for cancer research, with more than 80% saying they would give consent for this purpose. However only 26% said they would be willing for their tissues to be used for research on genetic cloning.

While three-quarters of respondents were happy for their tissue to be used to teach medical students, only half said they would give consent for children's tissue to be used for medical research.

The researchers, led by Michaela Goodson said: "Our study clearly showed that, in contrast to previous studies, a large minority of responders were not prepared to donate any of the listed tissues for research."

The team said the reluctance to donate children's tissue may also be the result of negative publicity surrounding Alder Hey and other scandals.

The research concluded: "Public education in understanding the principles and benefits of clinical research is an essential process towards the re-establishment of public confidence in medical research practice."