And an extra charge in some cases is added if a doctor is required to read the report.

Among the complaints received by the council was one from a woman who was given an incorrect report, diagnosing her with a serious illness.

Another woman criticised the poor attitude of a laboratory. She was undergoing an ultrasound examination on her breast when the machine malfunctioned and her breast was trapped.

Last year 94 complaints were received concerning health checks.

Seven were recorded in the first four months of this year.

Most of the complaints concern the quality of service, delays and misleading advertising.

The South China Morning Post reported the potential harm of undergoing unnecessary health checks in April.

The chairman of the Consumer Council's community relations committee, Larry Kwok Lam-kwong, said yesterday that frequent check-ups were not always to be encouraged because some examinations were not necessary for everyone. 'While some health-check packages may include basic check-ups, there are some which offer more expensive and potentially more risky procedures,' he said. 'These are only suitable for those at higher risk of developing particular diseases.'

He repeated the Health Department's recommendation that cervical cancer is the only type of cancer where screening for early detection should be done annually.

'People are recommended to consult their family doctor first before enrolling in any check-up package. With medical advice, they can choose to undergo tests which they really need,' Mr Kwok said.

The council survey of 55 health-check packages found some offered by medical laboratories included a provision that a doctor's interpretation of the reports was available on request for an extra charge. If no request was made, laboratory analysts would do the job. 'Clients might be misled when the report is read by someone who is not a medical professional. It is easy to introduce erroneous readings,' Mr Kwok said.

Council chief executive Connie Lau Yin-hing said the public should keep a cool head when faced with aggressive advertising for expensive health-check packages.

People 'should consider their needs and assess if it is needed according to their age, sex, health status and family history', she said.

Mr Kwok advised the public to choose laboratories recognised by the Hong Kong Accreditation Service and examine quality as well as the price of a service.

Healthy profit

The Consumer Council examined 55 health-check packages

The packages assessed ranged in cost, in Hong Kong dollars, from $280 to $4,980