The chief executive of the Child Exploitation and Online Protection (CEOP) Centre has quit following the government's decision to merge the centre into the new the National Crime Agency.
Jim Gable believes the proposal, due to come into force in 2013, is "not in the best interests of children and young people". The CEOP, which was set-up in 2006, is currently affiliated to the Serious Organised Crime Agency (SOCA).
The CEOP said the merger was announced a short while ago, and Gamble has offered his resignation to the Home Secretary with a four-month notice period.
The CEOP developed a 'panic button', which has been installed on a number of social networks, including Bebo, and allows users to report suspicious behaviour. Earlier this year, Facebook installed the button, despite initially refusing.
"The Government recognises the importance of child protection and wants to build upon the work of CEOP, but does not necessarily feel this is best done by creating a new quango," said Home Secretary Theresa May before praising Gamble and wishing him "all the best for the future".
However, Gamble's resignation has disappointed child protection charities.
"This is the worst possible news and a devastating blow for UK child protection - Jim Gamble changed the face of child protection for the better, forever," said the Phoenix Foundation. "We cannot begin to describe how disgusted we are with our own Government for betraying him and for betraying all of our children."