An Oxford University professor says children living in homes with high levels of radon gas or gamma radiation do not face a greater risk of developing cancer.

Scientists from the UK Childhood Cancer Study measured radon gas and gamma rays in the bedrooms and living rooms of 2,226 children with cancer and 3,773 healthy children.

They found that levels of radon, a naturally occurring radioactive gas, were no higher in the homes of children with cancer.

The amount of gamma radiation in children's homes also seemed to be unrelated to their risk of developing cancer.

Radon naturally seeps into many homes and rocks give out high amounts of gamma radiation. Prof Sir Richard Doll, of Oxford University, who is chairman of the study group, said: "Previous research has been inconclusive, so it's not surprising that parents have been worried. This study is the first in the UK to measure domestic levels of radiation and relate them to children's cancer risk, and it's pleasing to be able to ease those fears."

None of the six cancers analysised, including acute lymphoblastic leukaemia, brain tumours and Hodgkin's disease, showed a link between high levels of radiation and rates of disease.

Those who gave financial support included Cancer Research UK, the Leukaemia Research Fund, Medical Research Council, the Department of Health and companies belonging to the Electricity Association.