Note that the NSPCC and the police have the power to commence legal action so you would have to be careful what your start rolling that they would be duty bound to follow up. The NSPCC is not just a charity they actually have power to start an investigation.
http://www.essex.gov.uk/Health-Soci...ges/Children-at-Risk-of-Abuse-or-Neglect.aspx
^ Child and Youth Protection Services will deal with your concerns confidentially and professionally. Charities are powerless, CYPS have legal support, authority and powers.
It would appear they're not quite that powerless.