Investigating allegations of historic child sex abuse is the most difficult job I have ever undertaken as a journalist.

Normally in an investigation you can get documents, find trusted sources, and corroborate information.

 Child sex abuse is  by its nature a private act between two  people-one who is not capable of giving consent.

 The person who is abused is likely to  be damaged for life by such an experience and could find it difficult to relate to other people. So prior to the Jimmy Savile expose hardly anybody believed them.

 The perpetrator  who would suffer huge damage to his or her reputation if found out  will go to any length to cover their tracks -including, if the current  Met Police criminal investigation , Operation Midland, is to be believed, murder.

Rack this up and say you wish to uncover acts more than 30 years ago- when mobile phones  and the internet were science fiction- involving very, very powerful people in high places who can pull strings and you have made it doubly difficult.

That is why it is absurd  for the BBC to put out a documentary claiming to reveal the truth about the Westminster paedophile ring when the story is only half complete, when the police haven’t finished their investigation, and nobody has tested the evidence.

The result was a documentary that probably left the public confused, the police visibly annoyed because it could have put off new people coming forward to help them complete their investigations and the survivors who were interviewed by the BBC worried they had been traduced.

The programme was right to show that closed cases including paedophile teachers and headmasters , celebrities and other powerful people had been found guilty because brave survivors had come forward, been believed, and won justice in the courts.

They were also right to raise the questions of when a suspect should be named publicly – because of the damage it could cause to their reputation. But I have little sympathy for Harvey Proctor, the ex MP who protested too much, because he put into the public domain what the allegations were against him before an investigationhas concluded whether they could be true or false. He is no shrinking violet.

At the moment information about this dark side of British history is coming to light in a piecemeal fashion. So the BBC cannot possibly know the ” truth ” about events in the past. It would have been far better if the Panorama team, who say they have spent a year on this, had waited another year before promising to come forward with a considered judgement.

 I would like them to concentrate on how the BBC has come to terms in tackling its own problem in handling the culture that allowed paedophiles like Jimmy Savile and Stuart Hall to thrive unchecked. They have a big report from Dame Janet Smith which will eventually have to be published – and they have already looked at the damage Jimmy Savile caused in the NHS. That would be a Panorama worth watching.