Counterfeiting gangs based in China are producing sophisticated copies of the world's best selling pharmaceuticals and in 2008 an estimated eight million of these deadly pills found their way to NHS patients in Britain, risking health of millions of people.

They were made in China, labelled in French and then shipped to Singapore. They ended up in Liverpool and from there were sold straight into the heart of the NHS, The Observer reported.

As the criminal investigation continues into how a fake consignment of Zyprexa, an anti-psychotic treatment prescribed for schizophrenia, infiltrated Britain's healthcare system last year, evidence is mounting that sophisticated counterfeiting syndicates are increasingly targeting Britain's network of high-street chemists, hospitals and GP surgeries.

Figures collated for the first time reveal that British border officials seized more than half a million counterfeit pills destined for the NHS and high-street chemists last year, an amount equal to the quantity of counterfeit drugs found in the whole of Europe in 2005.

So vast is the scale of the threat from fake medicines that public confidence in the NHS could be "completely undermined", according to legal experts. Health officials also warn that the health of millions of Britons is potentially at risk, the paper said.

Customs officials and the Home Office border agency intercepted more than three million pounds of fake life-saving medicines for ailments such as heart disease and cancer in the first 10 months of 2008. Three consignments were each larger than 100,000 pills.

Latest government intelligence indicates that criminal gangs operating largely out of China have shifted away from selling fake "lifestyle" drugs such as Viagra on the Internet and are now concentrating on supplying counterfeit life-saving medicines to the NHS, The Observer reported.

Profits are potentially greater, with the high price of medicines in the UK ensuring that it has emerged as a prime target for criminals, according to the government agency that oversees the safety of medicines, the Medicines and Healthcare Products Regulatory Agency.