The chief executive of the Child Exploitation and Online Protection centre (CEOP) has resigned.
Jim Gamble said he was concerned about proposals to incorporate CEOP into a new National Crime Agency.
Accepting his resignation, Theresa May said: 'As chief executive Jim Gamble has done a great job at CEOP and made a huge contribution to protecting children.
'I wish him all the best for the future and arrangements for his successor will be outlined in due course.
'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.'