OSLO, NORWAY — A law that took effect Jan. 1 forbids Norwegian citizens from paying for sex — at home or abroad. Henceforth, any Norwegian caught paying a prostitute could face a stiff fine and as many as six months in prison.In cases of child prostitution, sentences could extend to three years.

Authorities said they hope penalizing consumers instead of purveyors will serve as a deterrent to sex tourism and street prostitution.

“We think buying sex is unacceptable, because it favours human trafficking and forced prostitution,” Deputy Justice Minister Astri Aas-Hansen told the AFP news agency.

Sweden and Finland have similar laws, but Norwegian enforcement agencies are authorized to use controversial measures like wiretapping to uncover evidence of wrongdoing.

In conjunction with criminalizing the actions of “johns,” Norwegian authorities also are offering working girls free education and substance-abuse treatment in an effort to get them off the streets.

Local media have reported a decrease in the number of hookers on Oslo’s thoroughfares since the law went into effect, but critics continue to predict the legislation’s primary result will be to drive prostitution underground.