Hannah Smith death: Ask.fm 'to help police inquiry'
6 August 2013 Last updated at 22:48 BST
The father of a 14-year-old-girl, who was found dead in her bedroom on Friday, says she was driven to suicide by cyber bullying.
Hannah Smith, from Lutterworth in Leicestershire, was apparently taunted about her weight and appearance by anonymous users on the social networking site ask.fm.
Her father, Dave Smith, has called for stricter controls on all internet sites used by children.
Sian Lloyd reports.