The Third Sector (or the 'third way' - sound familiar?) as opposed to the Public and Private Sectors, is the term used to describe voluntary/community organisations/groups etc who provide public and charitable services. The factor being that it is local residents who set up and run these groups for the benefit of their communities.
A lot of public money is given to this sector with little that is apparent in the way of accountability or regulation.
Central government has been heavily promoting the use of the third sector to 'deliver' public services with the argument being that local residents will/can provide better services to their communities. (like the argument that free market enterprise is good and beneficial to all). However ideological this argument may be in theory, in practice the third sector in many cases is failing to deliver.
The main body responsible for registering and 'monitoring' (but not regulating it appears) charities is the Charity Commission, and from experience seems to be just another ineffective and costly government quango. The charity commission is only likely to get involved with larger charities and only concerning specific maladministration. Remember that many of the users of community groups and charities are elderly and vulnerable.
Many charities and other voluntary groups do a great job in delivering what they say they will deliver and behave in a professional manner, but there are some who do not do this and it is these that raise concerns.
Camden council does have the authority to intervene when registered charities in their borough behave corruptly. And given that many of these charities have the elderly and vulnerable as their clients, Camden council should be doing more to protect them from abuses committed.