Facebook has seen a sevenfold increase in young people reporting suspicious behaviour online since it introduced a so-called panic button in Britain last month, investigators said yesterday.

A total of 211 Facebookers have used the button since July 12, compared to 28 who reported alleged abuse through the site in the month before its introduction.

The application, which is optional and advertised to Facebook users aged 13 to 18, aims to prevent predatory adults from “grooming” unsuspecting young people online.

Calls for a panic button grew in Britain after a 33-year-old convicted sex offender was jailed in March for the rape and murder of 17-year-old Ashleigh Hall, who he met on Facebook by pretending to be a teenage boy.

The new figures were reported by Britain’s Child Exploitation and Online Protection Centre (CEOP), which provided the ClickCEOP application – nicknamed the panic button by media – in a joint initiative with the social networking site.

It added that a total of 55,000 people had downloaded the application.

“There is no single answer to making the internet safer but CEOP have taken a great step forward by setting up their ClickCEOP page,” said Joanna Shields, Facebook’s vice president for Europe, the Middle East and Africa.