People searching the web for information on suicide are more likely to find sites encouraging the act than offering support, a study says.
Researchers used four search engines to look for suicide-related sites, the British Medical Journal said.
The three most frequently occurring sites were all pro-suicide, prompting researchers to call for anti-suicide web pages to be prioritised.
Mental health campaigners said such sites preyed on vulnerable people.
Unlike in some countries, pro-suicides sites are not banned in the UK.
These sites are preying on vulnerable and lonely people
Marjorie Wallace, of Sane
The 1961 Suicide Act says it is illegal to aid, abet, counsel, procure or incite someone to kill themselves.
But to be successfully prosecuted the individual has to have knowledge and participated in the suicide.
The researchers, from Bristol, Oxford and Manchester universities, typed in 12 simple suicide-related search terms into the internet engines.
They analysed the first 10 sites in each search, giving a total of 480 hits.
Altogether 240 different sites were identified.
In total, 90 hits (19%) were for dedicated suicide sites, half of which were judged to be encouraging, promoting, or facilitating suicide.
Some 43 hits 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.
A further 44 (9%) hits were sites or pages that provided information about suicide methods in a purely factual (24), partly joking (12), or completely joking (eight) fashion.
Twelve hits were chat rooms or discussion boards that talked about methods of suicide.
In contrast, sites focusing on suicide prevention accounted for 62 hits (13%), and those forbidding or discouraging suicide accounted 59 hits (12%).
Lead research Lucy Biddle said that because of the law, self-regulation by internet providers and the use of filtering software by parents were the main methods used to try to prevent the use of pro-suicide sites.
But she added: "This research shows it is very easy to obtain detailed technical information about methods of suicide."
She said internet service providers could pursue strategies that would maximise the likelihood that sites aimed at preventing suicide are sourced first.
Marjorie Wallace, chief executive of the mental health charity Sane, agreed something should be done.
"We remain deeply concerned about the possible influence of the internet on suicide rates, not least the ease with which information about particular methods can be found with a simple web search.
"These sites are preying on vulnerable and lonely people."
But the UK Internet Service Providers Association said it did not have editorial control over site prioritisation and would only take sites down if they were illegal.
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