A Wisbech paedophile who worked with young people in the town for three years without a police check, is among 101 people taken to court since David Cameron announced a crackdown on child porn.

Of those charged, one in three held positions of trust or had roles that allowed them access to children, including doctors, teachers, scout leaders, clergymen, police officers, a magician and a Santa Claus.

Only two of those convicted were women. Six out of ten of them were jailed. Others were given community orders or told to do unpaid work.

Claire Lilley, head of child safety online for the NSPCC, said: “The scale of the problem is shocking and even more so because of the number of people who hold positions of trust in our communities.

“This is just a fragment of the hundreds of other similar convictions during the same time.

“It is a myth that there is no harm in just looking at these images. Defenceless babies and children are being molested to feed the appetite of offenders, and that demand is just not going away.

“The Prime Minister made a bold attempt to tackle this problem, but it is clear that, two years after he called for a crackdown, the scale of the problem is proving to be massive. We need urgent action to prevent this horrendous abuse from appearing online.”

“A recent report by Her Majesty’s Inspectorate of Constabulary showed that over half of investigations into online child abuse are inadequate.”

An NSPCC snapshot has revealed that sex offenders are convicted at the rate of two a day and in two years more than 4.5 million images have been seized by police.

The snapshot includes Andrew Mattless of Edingburgh Drive, who forged documents to be able to work with the town’s Sea Cadets without a police check.

Mattless was jailed for 20 months in February 2014 after pleading guilty to possessing 112 extreme animal porn images and more than 250 child porn images.

He was further charged with possessing an extreme image of somebody performing an act of intercourse on an animal and possessing 111 extreme pornographic images of a person performing oral sex on an animal.

Four of the offences were images rated at level five, considered the most offensive type of photo.

The father of three had previous cautions for indecent images and common assault on a child.

The previous cautions for child porn and assault were taken off paperwork that Mattless showed to the cadets to prove he was cleared to work with children and young people.

David Cameron promised law enforcement agencies would be given more powers to stamp out vile images that were hidden ‘in the darkest corners of the internet.’

But despite the positive steps taken the NSPCC said the number of cases reaching court were still just a fraction of overall offending with around 50,000 people in the UK thought to be making and sharing images.

Court cases have revealed how offenders are devising new ways to share abuse, including live streaming the assault and rape of young people.

More than a quarter or those charged were convicted of other sexual crimes, including grooming, voyeurism and indecent assault.