Almost half of men who pay for sex have a partner, a study has concluded.
Many men paid for sex locally
Glasgow's Sandyford Initiative analysed data on 2,500 men who attended a sexual health clinic. One in 10 said they had paid for sex.
Of those around one in four said they repeatedly used prostitutes, 43% had a partner and 20% had a sexually transmitted infection.
Data collected between October 2002 and February 2004 appears in the journal Sexually Transmitted Infections.
The researchers warned that their figures could be an under-estimate of the true numbers who pay for sex.
They found that over half of those men who admitted paying for sex had done so while abroad, while 40% said they had paid for it locally.
Just under 2% said they had paid for sex both in the UK and abroad.
Unprotected vaginal sex was relatively rare, but more common in men who had paid for sex abroad. Unprotected oral sex was more common among the men who paid for sex locally.
And more than half (56%) of men who paid for unprotected sex said that they had a partner.
Similar numbers of men reported paying for sex in saunas and on the streets.
The researchers said this suggests that there needs to be a rethink about health initiatives for sex workers, which have largely been targeted at those involved in street prostitution.
Sexually transmitted infections found among the men who took part in the survey included gonorrhoea, chlamydia, and syphilis. However, none had HIV.
Mental health issues
Peter Baker, chief executive of the Men's Health Forum, stressed the number of men who paid for sex in the general population - rather than among a group who attended a sexual health clinic - was likely to be much lower.
But he said the figures appeared to confirm a rising trend in the number of men who paid for sex.
"Partly it is because of the increasing instability and fragility of relationships," he said.
"It may also be because many men are experiencing high levels of stress, anxiety and depression but are reluctant to seek help - or even just talk about their problems.
"What some do instead is seek respite through alcohol, drugs or sex."
Mr Baker said there was also less of a taboo about paying for sex. Greater access to sexually explicit material through the internet might also encourage the desire for sexual experimentation.
"There is a need to educate men as well as sex workers about safer sex.
"We have to acknowledge that many men will pay for sex and that they need to know more about condoms, the safety of oral sex, and how to access sexual health services."