Convicted sex offenders are free to read pornography in their cells, a Swedish court ruled, saying the country's prison system had no right to deny an imprisoned rapist access to his porn magazines.

Officials with the Swedish Prison and Probation Service had argued that reading porn would interfere with the man's rehabilitation program. They also said the magazines posed a security problem for staff and other inmates because they could increase the risk of the man relapsing into criminal behavior.

But the Supreme Administrative Court in Stockholm, whose ruling last week cannot be appealed, said the prison service failed to prove that the magazines could "jeopardize the security of the institution."

Prison officials said they had asked the government to change the law so that they could continue to ban porn magazines at the Nordic nation's prisons.

"It increases the risk of assault for other inmates and it is provocative for personnel," Elisabeth Kwarnmark, a prison service psychologist, said in response to the ruling.

Kwarnmark said that other pornographic material, such as adult movies, channels and Web sites, is not permitted in Swedish prisons. Child and violent pornography are also banned.