An internet monitoring group has said it has received a record number of reports of online child pornography in the first six months of 2006.

Half of all content traced back to the United States.

The Internet Watch Foundation said it had received 14,313 reports between January and June, up almost a quarter from the same period in 2005, involving 4,908 cases where investigators found potentially illegal content, an increase of nearly 50%.

IWF chief executive, Peter Robbins, said that 2006 saw a record number of websites confirmed to contain evidence of child abuse.

The report said the increase did not necessarily mean there were more illegal websites being set up, but could reflect a greater public intolerance and knowledge of where to report such sites.

Just over half of all the child abuse content had been traced to the US, with 15% traced to Russia, 12% to Japan, 9% to Spain and 0.2% in the UK.

Despite warnings to relevant authorities around the world, some websites with child abuse remained accessible for up to five years, according to the IWF.

One website, first reported to the IWF in 1999 and which had been reported 96 times since, was still up and running despite 20 alerts to the relevant authorities.

The IWF said the new information underlined the need for unified international efforts, 'transcending borders and legal jurisdictions'.