Hillsborough Wikipedia posts 'hard to trace'
25 April 2014 Last updated at 22:52 BST
The Cabinet Office has said that it may be a challenge to find out who was responsible for using a computer in Whitehall to make offensive remarks about the Hillsborough disaster.
Alterations were made to the Wikipedia entry about the tragedy, in which 96 people were killed.
The Cabinet Office said the comments were "sickening".
Vicky Young reports.