SHOCKING as it was, there were many positive messages from this week's documentary The Secret Policeman.

Firstly, this was top quality investigative journalism. The BBC has had its share of knocks recently - some from this column - but this was brave, tenacious reporting on a matter of clear public interest.

Undercover journalist Mark Daly taught the police a thing or two about detection and, in doing so, helped root out evil. The idea that he might be prosecuted for damage - caused to a police vest by his pinhole camera - is absurd.

Secondly, the reaction of the police forces involved. Admittedly, given the case prepared by Daly, they had little option, but their condemnation of the appalling individuals and their sickening views was quick, unequivocal and sent a clear message to racists of all kinds - closet, covert or loudmouth - that there is no room for them in a modern police service. Those words must now be followed by equally swift action.

Finally, let's remember that people exposed in this programme are a minority - don't be fooled by their claim to speak for a silent majority.

What Daly found over several months was a handful - no more - of obnoxious individuals who are operating in an increasingly hostile environment. They are an endangered species which, quite rightly, no one is going to lift a finger to save. The dustbin of history is open and waiting for them and their views.

The environment is hostile to them as organisations, including the police, have moved on. They have systems which identify attitudes like this. They have training and development programmes which can change attitudes. And where that isn't possible, they have ways of dealing with those who can't or won't learn.

The culture in which we operate has changed too, so that more people accept that living in a multi-cultural society is a benefit, not a threat. The trickle of poison seeping from the snakes exposed in this film is very small compared to the positive work being done in schools, churches and mosques, in councils and voluntary organisations and sports clubs by people of goodwill of all races and creeds.

Because of them, how we approach issues of race, religion and diversity and how they are portrayed in the media has changed dramatically.

There's a lot more to do and no room for complacency. However hard it is, we have to keep questioning our own attitudes. The racists will linger on in increasingly pathetic, sad and bitter pockets. But their days are numbered. Let's hurry them on their way.

Try as I might, though, I can't glean anything positive from the latest outpourings of Paul Burrell.

Mr Burrell may currently be the conspiracy theorists' best friend, but I doubt if he will attract any sympathy in more rational circles.

Dignity and credibility are qualities which often go hand in hand, and this week, Mr Burrell has bidden them a no doubt lucrative, but permanent goodbye.