Local and regional newspapers are being urged to turn away advertisements for sexual services which may encourage human trafficking.
Many newspapers carry ads offering sexual services
The Newspaper Society is updating its guidelines on those adverts which should be accepted on classified pages.
It wants its members to be especially aware of the link between organised prostitution and human trafficking.
The society has already advised its members on how to spot adverts which might be promoting sexual services.
For example it tells them to be wary of ads for massage parlours, which might be a front for brothels.
The society, which represents most local and regional papers, is suggesting they simply refuse such ads.
It also suggests that payment be made by card or cheque so accounts can be traced, and that papers consult with police.
The updated guidance follows a meeting with Harriet Harman last year in her role as minister for women, the society is sending out updated guidance to papers which stresses the link between organised prostitution and human trafficking .
Ms Harman, now Labour chairman and the leader of the House of Commons, is concerned that a growing number of young girls are being smuggled into this country and forced into prostitution.