Social networking site MySpace is to introduce technology designed to identify and block convicted sex criminals. 

The site is hugely popular with teenagers, largely due to its entertainment and music content. But it has also become a target for paedophiles looking for underage internet users.

MySpace will use technology from Sentinel Tech Holding to identify and block users with a history of sex crimes.

The company's Sentinel Safe technology will allow MySpace to search state and federal criminal databases and remove profiles of registered sex offenders.

"We are committed to keeping sex offenders off MySpace," Hemanshu Nigam, chief security officer at the website, said in a statement, as reported by Reuters. 

The US has over half a million registered sex offenders, according to MySpace. The new service is the first US-wide database, combining data on sex offenders from 46 states.