MySpace.com, the fast-growing social networking site owned by News Corporation, is making further efforts to ease parental concerns about their children’s exposure to sexual predators while using the site by developing the first searchable database of registered US sex offenders.

In a partnership with Sentinel Tech Holding, an online identity and background verification company, MySpace said on Tuesday it would develop the database, which will include identifiable details of the 550,000 registered US sex offenders, such as name, age, physical descriptions and features such as scars and tattoos.

This information will be used to match with MySpace profiles, which will then be removed by MySpace staff.

However, the ability to take on a false identity and the fact that sex offenders do not need to register their e-mail addresses will limit the database’s effectiveness. MySpace has asked Congress to introduce e-mail registration legislation to make it easier to block sex offenders.

Such laws would also mean that failure to register an e-mail would constitute a violation of parole or probation.

“[This] is a strong step in the right direction but a gap will still exist in our ability to keep sex offenders off social networking sites until there is legislation that forces sex offenders to use registered e-mail addresses,” said Hemanshu Nigam, chief security officer at MySpace.

The rapid growth of MySpace, which was set up only three years ago, into the world’s most popular social networking site has raised concerns among parents, school and policymakers about the risks of this trend to children.

Social networks are particularly popular among teenagers, but many of them choose not to keep their identities secret.

MySpace has introduced other measures to ease concerns, such as an option to keep a profile private. Mr Nigam said he was hoping to work with law enforcement agencies in other countries too, reflecting MySpace’s expansion across Europe and Asia.