AN American man was sentenced to 10 years in prison yesterday for transporting and possessing child pornography following his arrest in Cambodia in 2008, United States media reported. 61-year-old Mark Stephan Freitag was arrested in the Kingdom after allegedly paying underage boys for sex, Arizona news website AZCentral.com said. Witnesses reportedly told Cambodian police that Freitag had been seen with boys between the ages of 6 and 14, and at least one of the boys later told authorities that Freitag had been paying for sex, AZCentral said. US authorities have stepped up their efforts against sex tourists through Operation Twisted Traveller, a scheme conducted in cooperation with Cambodian authorities through which Americans who commit sex crimes in the Kingdom can be prosecuted in the US.