Opening arguments will begin Wednesday in the case of a Missouri woman accused of using an internet social networking site to harass a teenage girl who later committed suicide.

Lori Drew, 49, is accused of creating a false MySpace internet account to pose as a teenage boy and send messages to 13-year-old Megan Meier.

She is charged under the federal Computer Fraud and Abuse Act with one count of conspiracy and three counts of accessing protected computers without authorization to obtain information. It's the first time the act, normally used to address computer hacking, has been used in relation to a social networking site.

Prosecutors allege it all started more than two years ago after Drew believed Meier had been spreading rumours about her own daughter in the Missouri city of O'Fallon.

Drew created a MySpace profile under the name Josh Evans and started an online romance with the girl, authorities allege. Drew's daughter and an 18-year-old employee are also accused of participating in the alleged hoax.

Meier hanged herself in her bedroom in October 2006 after the online relationship allegedly soured and she received cruel messages from the boy,  including one that said the world would be better off without her. Prosecutors allege the Josh Evans account was deleted after Meier died.

Defence lawyers say Drew was not home when that message was sent.

Authorities in Missouri investigated Meier's death but didn't lay any charges because the state didn't have any laws that applied to the case. The state has recently included cyberbullying as part of its harassment laws.

The case is being prosecuted in Los Angeles because MySpace computer servers are based in the area. Fox Broadcasting owns MySpace.

The indictment says MySpace members agree to abide by terms of service that include, among other things, not promoting information they know to be false or misleading; soliciting personal information from anyone under age 18 and not using information gathered from the website to "harass, abuse or harm other people."

Drew conspired to violate the service terms from about September 2006 to mid-October that year, according to the indictment.

Drew and her co-conspirators "used the information obtained over the MySpace computer system to torment, harass, humiliate, and embarrass the juvenile MySpace member," the indictment charged.

If convicted, Drew faces up to 20 years in federal prison.

With files from the Associated Press