A man has lost his home, his family and £300,000 after being jailed for downloading child porn.

Now a partner in the company on whose evidence he was convicted has had his controversial methods called into question.

David Mould, 48, believes his name would be cleared if probes were reopened into child porn cases investigated by ex-Sussex Police officer Brian Underhill and business partner Nicholas Webber.

Mr Underhill's blunders were blamed for the failure of the Crown Prosecution Service's case against Soham detective Brian Stevens, who had charges of indecent assault and downloading child porn suddenly dropped.

However, Mr Mould knows it would take a lot for his shattered life to recover from the stigma and trauma inflicted by his conviction at Hove Crown Court three years ago.

Although his wife stayed loyal, he was forced to leave the family home because he was denied contact with his two step-children.

He now lives a nomadic existence on a boat and has struggled to recover his professional reputation after serving a month in jail.

He is on the sex offenders' register, after being found guilty of downloading an indecent picture of a ten-year-old boy from a paedophile internet site and using it as background computer "wallpaper".

Mr Mould was convicted of two charges of making an indecent photograph, following key evidence from Mr Webber, who co-directs a West Sussex computer investigations firm with Mr Underhill.

Mr Mould's three-month sentence for downloading indecent imagery was reduced on appeal.

He served four weeks before it was overturned and he was released. Despite an appeal, his conviction was upheld.

He is backing calls for an inquiry into all the cases on which Mr Underhill and Mr Webber's firm has worked.

Mr Mould said: "My life has been ruined. To say this carries a stigma is an understatement.

"People who know me have backed me 100 per cent. But it's the people who don't know me who react badly when they hear of something like this.

"The family has had graffiti painted on the walls and windows smashed.

"The children are getting older now and understand things better but it's so hard not being able to see them.

"The police and social services interrogated anyone who knew me who had children, trying to catch them and me out but never found anything against me.

"I've got over a lot of the anger but I am still very bitter. I would like to see an inquiry into all the cases Underhill and Webber have covered, not just for myself but for the other people who may have become innocent victims.

"I've always been wary about media interest or making statements about my experiences but I've also always hoped something would come up to help my case get looked at again. This could be it."

The evidence against him centred on computer analysis carried out by Mr Webber, who showed the court specific internet sites featuring gay and paedophile pictures had been visited.

Mr Mould admitted that, two years previously, he had visited an internet newsgroup discussing paedophilia but insisted it was through curiosity.

He denied downloading any indecent images and said the list of newsgroup sites which appeared on his computer would appear on any machine which accessed the newsgroup system.

Mr Webber told the court the absence of certain computer files suggested Mr Mould had deliberately deleted indecent photographs.

Institution of Analysts and Programmers (IAP) president Jim Bates, who followed the trial, insisted: "There was no evidence presented that child pornography had ever been downloaded on this machine."

He has drawn up a report pointing out what he believes were crucial technical errors by Mr Webber.

Mr Mould said: "I was standing in the court listening in complete disbelief to what was being said about me. There had been a lot of talk in the papers about internet sites and I wanted to see some of the discussions but I never saw any images I would consider indecent or pornographic and I had never seen the picture they said was on my computer before."

The battle to clear his name through legal appeals and to try to gain access to his children through family court battles has cost Mr Mould more than £300,000.

In Mr Stevens' case, Mr Underhill decided a computer file containing some of the allegedly indecent images had been deliberately created to hide secret material.

He also believed an email sent from the computer on a specific date had been used to transfer some of those pictures.

However, when Mr Stevens' defence team contradicted these conclusions in their report on the laptop, Mr Underhill admitted he was wrong.

Prosecutor Andrew Campbell-Tiech told Southwark Crown Court these errors left them with "simply speculation and nothing more".

During a hearing last month, Mr Underhill told Southwark Crown Court he had "conducted or assisted" in 600 cases in 40 months.

The IAP doubts he could have worked on that many but believes about 50 cases need to be looked at urgently.

Four years ago Mr Underhill and Mr Webber set up Celt Limited, standing for Computers, Electronics and Lateral Thought, based in Church Road, Scaynes Hill.

The firm has advised computer crime units in police forces including the Met, Sussex, Essex and West Midlands.

Sussex Police set up anti-child porn crackdown Operation Chaucer as part of the nationwide Operation Ore last year.

A spokesman said they had not worked with Celt Limited during that time and used their own team of computer crime investigators.

Mr Webber and Mr Underhill have failed to respond to The Argus' requests for a comment.