As well as promoting the use of the CNEP ventilator for premature babies - a practise now abandoned in the UK - Professor Southall has also attracted controversy over his work on the use of secret video cameras to monitor parents suspected of child abuse.

However, Professor Southall is also credited with important research into cot death, which over-turned findings that the problem was due to the gaps in babies' breathing while they sleep.

His research into CNEP ventilators at North Staffordshire provoked intense scrutiny because parents claimed they did not give consent to their children taking part in the trial and they claim their signatures were forged.

And the technique that made his name, the pioneering use of covert video surveillance (CVS) to identify children at risk of child abuse, also drew stinging attacks from parents.

Cruel and sadistic attacks

The eight-year study, which started in 1986, found that youngsters aged between two months and 44 months were being deliberately injured in cruel and sadistic attacks by their parents or step parents while in hospital.

The most common method of abuse was suffocation, but deliberate fractures and poisoning were also uncovered by CVS.

Following detection of the abuse, 23 parents or step-parents of the 39 children identified as at risk by doctors, social workers and psychiatrists, were found to be suffering from the attention-seeking disorder Munchausen's Syndrome by Proxy.

As a result of the condition, parents harm their children in a bid to create situations where they are the centre of attention.

But despite Professor Southall, himself a father of four, being praised by a judge following a successful court action against one abusive mother, his efforts raised difficult ethical issues and sparked an angry response from parents.

Some parents complained that the hospitals involved - the Royal Brompton, in London, and the North Staffordshire Royal Infirmary, Stoke-on-Trent, were operating a policy of entrapment.

Covert filming led to a total of 33 parents or step-parents being prosecuted.