Israel fired artillery shells containing white phosphorus in its recent conflict with Hezbollah militants in the Lebanon, according to an official investigation by the United Nations.
White phosphorus is banned under the Geneva Convention when used against civilians or in civilian areas, although Israel insists that the shellswere directed against solely military targets.
However, the UN team failed to find any evidence that Israel used depleted uranium, enriched uranium or any other radioactive material in bombs dropped on Lebanon during the month-long war, which ended on 14 August.
Achim Steiner, under-secretary-general and executive director of the UN Environment Programme, said that samples taken by scientists had confirmed the use of white phosphorus in artillery and mortar ammunition by the Israeli military.
Mr Steiner also said that the scientific analysis found no evidence of penetrators or other metallic bomb components made of depleted or enriched uranium, as claimed by two British activists in a report published last month.
"No depleted uranium shrapnel, or other radioactive residue was found. The analysis of all smear samples taken shows no depleted uranium, nor enriched uranium nor higher than natural uranium content in the samples," Mr Steiner said.
The samples taken by the UN for analysis were collected between 30 September and 21 October.
Three independent laboratories in Europe undertook the tests on behalf of the UN.
The findings conflict with a report by Chris Busby, a Green Party activist, and his colleague Dai Williams, an occupational psychologist, who claimed to have found evidence of enriched uranium in a sample collected from a bomb site in southern Lebanon.
The sample was collected by Mr Williams during a visit to the Lebanon who passed it on to Dr Busby before it was sent for analysis at the Harwell Laboratory in Oxfordshire, which is used by the Ministry of Defence.
"We are concerned that UNEP don't know what they are doing. Earlier (in 2001) they were useless at finding depleted uranium in Kosovo due to wrong choice of instrumentation. In addition, owing to the disagreements about health effects they may cover up any findings or dismiss them," Dr Busby said last night.
Dr Busby suggested that Israel was trying to cover up the use of depleted uranium in its bombs by deliberately adding enriched uranium, which would make the final radioactive signature after the explosion similar to natural uranium.
Other experts however dismissed the idea as implausible.
