Online sex addiction is growing to epidemic proportions across all levels of society, according to US psychologists.

The internet's anonymous nature and instant gratification is responsible for the dramatic growth in cybersex addiction that can affect everyone from housewives to high-flying executives, said experts at a seminar at the US National Council on Sexual Addiction and Compulsivity.

Cybersex addiction is becoming particularly prevalent among women who are lured by the interaction and safety zone offered in online chat rooms.

A study presented at the conference found that almost nine per cent of people who use the internet for sex spend more than 11 hours per week surfing for erotic content, while 15 per cent of all net users had visited an online sex chat room or pornographic site. Numbers were split equally among men and women.

US psychologists believe that the internet is creating a new breed of sexual addiction known as "hypersexuality" - a compulsive need for cybersex that is above and beyond relationships offered in the real world.

"The pain that this can tear through a relationship is deep, and it's profound," said Kimberly Young, a psychologist at the Sierra Tucson clinic in Arizona. "Relapse is just a click away."

Psychologists at the conference said cybersex addiction should be treated seriously, requiring therapy just like eating disorders. They recommended telling patients to delete their internet bookmarks and limit the time they spend online.