Changing the law on organ donation to a system of presumed consent may not boost the numbers needed for transplants, an expert has said.

Dr Rafael Matesanz, director of the National Transplant Organisation in Spain, which has the highest donation rates in the world, said presumed consent may not be the answer in the UK.

A Government taskforce is due to report on the controversial issue in the next few months.

But experts voiced fears over such a move, saying other steps should be tried first.

Under a system of presumed consent, a person is presumed to offer their body after death for organ donation unless they "opt out" of doing so.

In practice, families would still be consulted on whether they were happy for their relative's organs to be removed.

Dr Matesanz said Spain had a system of "soft" presumed consent, which means an opt out system is in place but families still get the final veto.

He said donor numbers in Spain had risen after the introduction of highly-skilled and trained doctors, who worked in intensive care units but also acted as transplant co-ordinators.

Special training in approaching bereaved families had led to a boost in donor numbers, alongside the national co-ordination of efforts to raise the profile of organ donation.

"All intensive care doctors receive training on how to detect possible donors and how to approach the family," he added.

Dr Matesanz said moving to a system of presumed consent in the UK would not offer a "magic solution".

Such a system could be good if the population at large agreed with the move, he said.

"But trying to modify a situation in the country by changing the law is, in my opinion, dangerous because all the efforts are concentrated on the law and ignore other aspects (of how donation can be increased)."

The UK has a low rate of organ donation compared to many other European countries.

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