There are more websites encouraging suicide than those offering help, new research has shown.

A study found that almost half of sites searched by people for information on how to commit suicide contained examples of how to take one's life while one in five hits were for "dedicated suicide sites".

Half of these were found to be "encouraging, promoting or facilitating suicide," researchers led by Lucy Biddle, professor of epidemiology at the University of Bristol, said.

The research showed media reporting of suicide and its portrayal on television are known to influence suicidal behaviour, "particularly the choice of method used". However, little is known about the influence of the internet.

The team used four popular search engines - Google, Yahoo!, MSN and Ask15 - to search the web in May 2007 for sites providing instructions and information on methods of suicide.

The researchers selected 12 terms that were entered into each search engine in turn. The first ten hits retrieved by each search were then analysed, with a total of 240 sites identified and 480 hits reviewed.

The terms used were: suicide; suicide methods; suicide sure methods; most effective methods of suicide; methods of suicide; ways to commit suicide; how to commit suicide; how to kill yourself; easy suicide methods; best suicide methods; pain-free suicide and quick suicide.

The authors said: "Just under a fifth of hits (90) were for dedicated suicide sites. Half of these were judged to be encouraging, promoting, or facilitating suicide; 43 contained personal or other accounts of suicide methods, providing information and discussing pros and cons but without direct encouragement; and two sites portrayed suicide or self harm in fashionable terms."

Twelve hits were of chatrooms or discussion boards that talked about methods of suicide. Sites focusing on preventing suicide or offering support, and sites forbidding or discouraging suicide, accounted for 62 (13 per cent) and 59 (12 per cent) hits respectively.

"Dedicated suicide sites and sites giving factual information about suicide had the highest proportion of number one ranks across searches (25 per cent and 27 per cent, respectively of all first ranked sites)," the study said.

A fifth (21 per cent) of support or prevention sites and 55 per cent of academic or policy sites, and all news reports of suicides also provided information about methods, the study found.

The study comes as police continue to investigate another apparent suicide in Bridgend, south Wales. There have been 18 deaths in the area so far over the past year.

South Wales Police insists it has discovered no evidence of a link between the deaths.

While many of the youngsters used social networking websites, such as Bebo and MySpace, the force has found no suggestion of any link between the deaths through the sites.

Nor has there been any evidence of a "suicide pact" between any of the teenagers, it said.

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