Dallas ? Illegal online sales of prescription drugs look to be on the rise.

A study from the National Center on Addiction and Substance Abuse released Monday says more Web sites are popping up, offering prescription medicines like OxyContin, Vicodin, Xanax and Ritalin.

The center’s chairman – Joseph Califano – calls the online market for controlled drugs a “candy store.” Califano said the government needs to tighten laws that regulate Internet sales.

The center checked Web sites for one week every year over the past three years. The study has more sites offering drugs without prescriptions. The number has been increasing since the annual review began three years ago.