A leading medical professor has challenged the government's plans to overhaul the human organ laws.

An expert on pathology warned on Monday that the Human Tissue Bill could have implications on medical science beyond those intended by ministers.

Professor Peter Furness, Professor of Renal Pathology at Leicester University, said the bill had much wider implications than the controversy surrounding the taking of tissue and organs from the dead.

The bill was ordered following the inquiry into the organ retention scandal at Liverpool's Alder Hey hospital where organs were taken and kept without consent from relatives.

Professor Furness warned that as the bill stands at the moment then in theory, the training and work of NHS staff could be affected.

"It seeks to prevent the abuse of post-mortem tissue - but it goes much wider than using tissue and organs from the dead; it applies to anything which contains human cells," he said.

"At least in theory, this law could make it a criminal offence to train NHS laboratory staff how to do their work, if that training uses a sample of urine or spit which has been discarded, unless the originator has given explicit consent. The penalty could be three years in jail and a large fine."

He argued scientists have no alternative in many cases but to use human tissue and questioned whether the risks for patients justify such severe penalties.

"A 'one size fits all' solution to a serious problem which captured the public imagination is in danger of having consequences far beyond the intentions of those who campaigned for or drafted the Bill. Consent, which is at the core of this bill, must be adequately informed if it is to be valid," he said.