Soliciting, kerb-crawling and operating brothels are illegal in Ireland but men can exchange money with a prostitute in private without breaking any laws.

Det Insp Jonas Trolle, from the Stockholm Police Department, said those using prostitutes were supporting and financing international criminal gangs.

"If you want to fight against trafficking in human beings you have to start with the demand," he said.

It is thought there are 1,000 women involved in prostitution in Ireland at any one time, with 800 being advertised on the internet.

Under the Swedish law, introduced in 1999, a man caught buying sex will be hit with a fine based on their income, with penalties ranging from €1,500 to €7,000.

The prostitutes are treated as victims who have been exploited.

Mr Trolle said that before the clampdown there were around 100 prostitutes on the streets of Stockholm, dropping to roughly 20 now.

The detective inspector, who heads a trafficking unit in the Swedish capital, said targeting the demand for sex squeezes profits for pimps and drives operators out of the country. The top officer said the law was widely accepted in Sweden, with around 80pc of the public backing the legislation.

Norway, Iceland and Finland have adopted versions of the legislation and Mr Trolle said he hopes both Ireland and the UK will consider similar models.

The conference included calls from anti-sex-trafficking groups for similar laws here.

Grainne Healy, co-ordinator of the Dignity Project, an interagency initiative working to deliver quality services for sex-trafficking victims, said: "There has been a decrease in the number of women being trafficked into Sweden since the criminalisation of the purchase of sex."