Because of the work on the evidence of the fish key ring, this became one of the most exhaustive investigations done by the programme under producer Peter Hill. Literally, every producer of such fish key rings in the world was contacted. Every retailer in Bradford was visited - as were all the distributors in England of such fancies.

It became clear during the early stages of the investigation that the police in Bradford had either lost or thrown away the original key ring. However, the Defence solicitor had hired a particularly diligent forensic scientist who had taken such a detailed description of it ( there were no police photographs of it) that retailers readily identified as distinct from all others on the market. The police took to following the "Rough Justice" researchers around Bradford - asking retailers for the description of the key ring that the researchers had mentioned. It seems to have been the only means of getting the information they had thrown away.

The "Rough Justice " team suffered more harassment from the police on this case than on any other case. On one occasion the team was tipped off that their next interview had been infiltrated by the police - an officer was posing as a relative of the next interviewee.

Christine Aldred - who identified the "Carol key ring" for "Rough Justice" was threatened by a well-known "copper's nark" that she would find his foot in her throat if she talked to the BBC.

This kind of action culminated in a meeting Peter Hill had with a senior officer in Bradford - where the officer claimed that the police thought the camera crew and research team were students from Leeds University messing around during a Rag Week! That officer did not realise that the "Rough Justice" team regularly used surreptitious recordings in such circumstances - for their own defence against the police.

The most difficult person to approach was the mother-in-law Vera Smith. She refused all overtures and objected when her photograph was taken, perfectly legally, in a public place. Having started the campaign against Steel, she wished to avoid any personal responsibility for her actions.

One of the more intriguing aspects of the "Rough Justice" research was the hypnosis session conducted on the man who saw the Austin Cambridge car near the scene of crime at about the time of the murder. Comparing his original statement with the hypnosis recollection, the most striking aspect is the description of the back of the car, which convinced everyone on the team that the car was an Austin Cambridge and not a Morris Oxford, which is very similar.

The most difficult technical aspect of the programme was covering the confession. Reading it alone would have taken many minutes - and would have been boring. Further, the best way to look at the confession would be in situ - to see how Steel's version matched the reality of the terrain. Martin Young and Peter Hill, who scripted the programme, asked Paul Wilkinson - Steel's friend and no relation to Carol - to re-trace the route mentioned by Steel, and read out key moments of the confession at the relevant locations.

The most amusing visual - and perhaps the most telling - moment in the programme was when Martin Young released a large balloon on a string whilst standing at the back door of Steel's house. The camera was placed in the position Carol had been in when Steel had claimed to have seen her. The balloon was above the roof of the house before the camera saw it! It demonstrated that Steel could not possibly have seen Carol as he had described it in his confession.

"The case of the Tell-tale Fish" as this programme was called, was the penultimate programme by Martin Young and Peter Hill. Lord Lane was already enraged by their earlier work and determined to put them out of business.