A Swedish law punishing the purchase - not the sale - of sex has been very effective in reducing street prostitution but could be strengthened by doubling the prison sentences, a justice ministry report said yesterday.

The ban on buying sexual services went into effect in 1999, the report said, and since then "street prostitution in Sweden has been halved."

"This reduction may be considered to be a direct result of the criminalisation of sex purchases," it said, acknowledging however that Sweden still faced the growing challenge of prostitution over the internet.

In 1998, before the Swedish law went into effect, Stockholm counted 280 street prostitutes. By 2008, there were only 180 left, according to official statistics quoted in the report. 111

Before Sweden became the first country in the world to criminalise buying sex, the number of street prostitutes in its capital was on par with the number in the capitals of neighbouring Norway and Denmark.

But while Stockholm had halved the number of street walkers during the decade ending in 2008, they had multiplied in Copenhagen and Oslo during the same period, the report said.

Norway introduced a similar law to Sweden's on January 1, 2009.

The report, which was handed over to Justice Minister Beatrice last Friday, called on lawmakers to go even further and to double the sentence for sex purchasers from the maximum six months prison term today.