The International Agency for Research on Cancer has found that the risk of melanoma - the most lethal form of skin cancer - increases by 75 percent in those who start using sunbeds before the age of 30.

"The use of sunbeds is carcinogenic to humans. It causes melanoma of the skin, and melanoma of the eye," said Vincent Cogliano, a researcher who led the new study, findings from which were published in the British medical journal The Lancet Oncology.

Sunbeds, which emit a higher concentration of ultraviolet rays than sunlight, had been classified in 1992 as a "probable" cancer agent. Since then the WHO and overseas agencies have cautioned against their use.

Dermatologist Louis Shih Tai-cho said the devices should be outlawed to avoid health risks.

"It is like smoking. As a doctor, I will tell you one drag is still too much," said Shih, adding that both UV A and B rays may cause cancer in addition to causing early aging of the skin.

However, the new findings are disputed by the Sunbed Association, an industry lobby group based in Britain.

"The relationship between UV exposure and an increased risk of developing skin cancer is only likely to arise where over-exposure - that is burning - has taken place," it said.

The Hong Kong Anti-Cancer Society says the number of diagnosed skin cancer cases rose nearly 200 percent between 1994 and 2004.

There is currently no regulation of sunbeds in Hong Kong whereas in some Western countries those under 18 are prohibited from using them.

Shih said people should avoid both solar tanning and sunbeds as much as possible, recommending that those keen on a bronzed look use self-tanners instead as they pose a lower health risk.

"Many models have given up on sun tanning and turned to self-tanners because they are much safer and better for the skin."

A Department of Health spokesman said it is aware of the report and will discuss whether sunbeds should be subject to regulations in the long run.

However, he urged the public to be aware of the adverse effects of using indoor tanning facilities.

Although there is no local evidence, data or study on the relationship between sunbeds and skin cancer, the use of sunbeds and other artificial UV light equipment without supervision is strongly discouraged.

The department will take into account the latest scientific evidence and data, as well as advice from health authorities in other countries, regarding the use of tanning devices.

The public should avoid going out when the UV index is high, use sunblock where necessary, wear long-sleeved clothing and maintain a healthy diet to reduce skin aging..