In November last year, “Kiki”, a primary teacher in London, started a discussion topic on the TES online forum. “Has anyone noticed that Sparklebox has been blocked again by various LAs (local authorities)?” she asked. “They are claiming it is for safeguarding reasons. It is an amazing website which cuts my resource-making time by 50 per cent. Does anyone know what the real reasons behind the block are?”

Sparklebox is a website with thousands of free primary school teaching resources available for download. As well as the wealth of material available, what made it so appealing for teachers was that resources were categorised by subject as well as by type and could be previewed before they were downloaded and printed out.

As one of the biggest repositories of online resources - relied upon by thousands of teachers for lesson planning - the speed with which Sparklebox had been placed out of bounds caused frustration and bemusement.

While many teachers were left in the dark, those who had an inkling about what was going on could not quite believe what they were hearing. “We have been given a reason that I quite frankly find very hard to take on board and would like to try and find out if it is true or not,” wrote a teacher on the TES forum.

Eventually, the reason for the embargo became clear. On January 8 this year, Samuel Kinge, the creator and editor of Sparklebox - and a former teacher - was convicted at Worcester Crown Court of downloading 424 indecent and fake photographs of children. He was sentenced to a year in prison. The man behind some of the most widely used primary school resources was a paedophile.

In the days following Kinge’s conviction, the explanation for local authorities’ ban of the site at last became public. The effects rippled through schools across the UK. While many learning grids subsequently lifted the ban (there is no evidence to suggest that Kinge involved Sparklebox in any of his offences) many teachers felt it would be immoral to use the site because of its association with a sex offender. Although Sparklebox was a one-man band, it continues to be available online while he is in prison.

“Everyone was completely taken aback,” says Zena Fish, a Year 3 teacher in Wandsworth, south London. “Our headteacher told us in the morning meeting. People couldn’t believe it. I had a discussion with my mum as well. She’s a high-level TA and she was really shocked. Everyone was saying: `Have you heard?’”

This was the second time Kinge had been convicted for child pornography. In 2005, he was jailed for nine months for making and owning indecent and explicit images of children. Then 23, he had been working as a reception teacher at a primary school in Warwickshire.

He was also banned from using the internet, although this was lifted on appeal after his lawyers said it would prevent him from working after his release. But he was also ordered to register as a sex offender and banned from working with children indefinitely.

On his release, Kinge changed his first name by deed poll from Daniel to Samuel and set about building what would turn into one of the most successful education websites in the UK.

At first, everything seemed to be going smoothly. But it was a teacher who first made the link between sex offender Daniel Kinge and Sparklebox creator Samuel Kinge. Early in 2009, this teacher voiced their concerns on an online education forum.

Alan Earl, a police intelligence agent who was working as a harm reduction officer with the South West Grid for Learning at the time, saw the allegations and decided to investigate. “I did a bit of digging and found out that he was in fact a sex offender,” says PC Earl.

“I then had a further look at the site and realised there was a bit of social networking there, with a blog.”

This was crucial. The potential for children to get in touch with Kinge via his website meant he was breaking the prohibition on working with children imposed as part of his sentence in 2005.

As a result, police blocked the site early in 2009. In response, Kinge removed the blog and put out a statement denying what he called false rumours and malicious gossip. Ironically, a page of the website explains how Sparklebox ensures a “safe and risk-free browsing experience” by screening all advertisements to ensure they are “family-safe”.

The police concluded the site did not pose a risk. “The threat had been removed when he took off the social networking facilities,” says PC Earl. “We were managing the offender.”

But a few months later, Devon and Cornwall police found evidence to suggest that Kinge might be involved with child pornography once more. According to PC Earl, Kinge would regularly erase most of the images he had made and downloaded. But police eventually found 424 indecent images of children on his computer and in October last year he was arrested.

At this point, most of the learning grids in England blocked access to Sparklebox. But until Kinge had come to trial they were unable to say why. Many teachers were enraged about being denied access and accused local councils of taking an authoritarian stance.

Numerous theories bounced around the internet, many expressing dismay at not being treated like responsible professionals, capable of handling sensitive information. “Or is it a secret governmental conspiracy to force teachers to be creative and make their own resources? Who knows,” wrote one poster on the TES forum. However, the risk of prejudicing the court case prevented the reasons for blocking the site from being made public, according to PC Earl.

Police handling the investigation were torn as to how much information they could pass on. “The last thing we wanted was to stop teachers from accessing such a good learning resource. We were between a rock and a hard place,” says PC Earl. “My heart went out to the teachers. And the police really did feel for them. It’s not like they weren’t taking it seriously. But this is about child safety. That’s the most important thing - the kids come first.”

There is no definitive evidence that Sparklebox was ever part of Kinge’s child porn network. Teachers had been able to communicate with Kinge through the site’s blog, before it was taken down, and some had uploaded photographs of their pupils.

But was Kinge using any photos directly from the site? “We don’t know and we can’t prove it,” says PC Earl, who regrets that the police were unable to find out either way. Sparklebox was primarily for teaching resources, “but teachers were posting pictures of themselves and their children online,” he says.

In Wandsworth, Ms Fish’s classroom still bears the stamp of Sparklebox. Splat words - vocabulary that her pupils should know - are pinned to the walls as well as multi-coloured “word banks”. Displays for days of the week and eye-catching “sight” words are placed around the classroom. Most of them bear the Sparklebox tag. “They’re very visual and really colourful,” says Ms Fish. ”(The site) would save me from making my own.”

Primary school teachers are notoriously pressed for time. Anything that makes their job easier is welcomed with open arms, and Sparklebox in particular was embraced. For the first six months of 2009, it was the 50th most accessed site on the South West Learning Grid, with 27 million hits. The website filled a big gap in the market for early years resources in particular. No other site had such a range of free materials that could be ready for use in a matter of seconds.

News of Kinge’s conviction has put many teachers in a quandary. Although the site is still online, Ms Fish has not used it since. She does not want to support it any further, although she has not removed Sparklebox material from her classroom walls. “Is that wrong?” she asks. “I don’t think I’d throw them out but I’d probably cut off the Sparklebox (logo).

“I don’t want to support someone like that. I’m really shocked that someone who created such good resources could do something like that.”

The teaching community has now overwhelmingly rejected the website, if the numerous comments and forum posts about the subject on the TES site are anything to go by. Many want to dissociate themselves from it completely.

“I don’t feel comfortable with the association between a sex offender and the resources used to support children’s education,” says Tricia Oxlade, a Year 3 teacher in south-east London.

“My immediate reaction was to remove everything from my room. Luckily, I only had a few well-chosen ones.”

Others feel that the resources themselves are not to blame and there is no point in throwing out perfectly good teaching material. At Ms Oxlade’s school, the headteacher is still using certificates from the site.

“I have brought this up with some members of staff but no one else feels the same way as me about it,” she says.

“I am quite shocked at the double standards, especially when safeguarding is supposed to be a high priority. It seems that quality resources and the time taken to seek out, prepare and replace them is of a greater concern. I wish the headteacher, the senior management or the borough had taken a stronger stance on this issue. I feel loathing for the Sparklebox brand and, if I could, I would remove them from other classes, too.”

While the conspiracy theories about why Sparklebox was initially banned may have been far fetched, it exposed how dependent teachers were on one site. “I am tired of walking into every classroom and it all looking more or less the same,” wrote one teacher on the TES forums, who believes some kind of control over the site’s usage was necessary, regardless of the recent news of its creator.

“There are more learning boards (made by Sparklebox) than there are children’s work in many classes. I know it’s a hard, all-consuming job but children deserve to be taught in a stimulating environment - and that is not wall-to-wall Sparklebox.”

After the initial shock and anger, this energy is now being poured into seeking out alternative websites and resources to help primary teachers with their lessons.

Ms Oxlade has bookmarked a series of new sites and put a list of alternatives on the staff noticeboard. Teachers have also been sharing their own materials and lesson plans online by uploading them to websites, meaning that they can receive feedback about what’s working or tips on how resources could be improved.

There is no doubt of the extent to which Kinge’s actions have affected primary schools. Few teachers will now be able to think of Sparklebox without associating the site with a sex offender. But if the end result is greater diversity of resources, shared information between teachers and resources catered specifically for individual classes, one could argue that it is a good thing - for primary teachers and pupils.