Drug companies are accused today of endangering public health through widescale marketing malpractices, ranging from covertly attempting to persuade consumers that they are ill to bribing doctors and misrepresenting the results of safety and efficacy tests on their products.

In a report that charts the scale of illicit practices by drug companies in the UK and across Europe, Consumers International - the world federation of consumer organisations - says people are not being given facts about the medicines they take because the companies hide the marketing tactics on which they spend billions.

"Irresponsible marketing practices form a serious, persistent and widespread problem among the entire pharmaceutical industry," says the report, which analyses the conduct of 20 of the biggest companies, two of which are British. It calls for tougher government controls and for the companies to put their house in order.

Scandals such as the withdrawal of Vioxx, a drug to relieve pain and inflammation in arthritis, show that unethical drug promotion is a consumer concern, says the report. Merck withdrew the drug in September 2004, but allegedly knew it could increase the chances of heart attacks and strokes from 2000 and has been accused of manipulating study results to play down the risk. More than 6,000 lawsuits have been filed against the company in the United States by people who claim they suffered heart attacks as a result of the drug, or by their families.

Despite regulatory action against drug companies, the malpractice continues, says CI. Many people in the UK may feel they are secure because they trust their doctors to tell them which drug to take, but CI says there is no room for complacency when drug companies spend twice as much on marketing as on research - $60 billion last year (£33 billion) - but do not publish information on their drug promotion practices. Of the 20 companies, only Bristol-Myers Squibb provides a marketing code of conduct to consumers.

"One obvious area of concern is about how the promotion of drugs by the pharmaceutical companies to doctors can lead to irrational drug use," says Richard Lloyd, CI's director general. "There is a lot of evidence around of malpractice. This report has found that it is still going on and in a big way and it must be stopped."

More than half the companies looked at were implicated in controversies regarding their relationships to healthcare professionals between 2001 and 2005, says the report.

The British company AstraZeneca, for instance, has been criticised by regulatory bodies: it allegedly organised an event to promote its drug Crestor which included tickets for a musical, and provided flights and hotels for doctors to attend a conference on bipolar disorder on the French Riviera. AstraZeneca says all employees must now pass an exam on its code of conduct.

GlaxoSmithKline, Britain's largest drug manufacturer, is under investigation by German and Italian authorities for alleged corruption of doctors - at least 1,600 in Germany and more than 4,000 in Italy, where the illegal gifts were said to amount to €228 million (£156 million) from 1999 to 2002. GSK says it has since established marketing codes. New staff have to pass a test on the code of practice. The report points out that in 2004, 87 employees were dismissed or agreed to leave the company voluntarily as a result of breaches of the codes, and that sanctions such as written warnings were imposed in 109 cases.