Rhodium is being touted as the basis for a potential cancer treatment being developed by American scientists.

A team working at Purdue University say that new research into light therapy suggests that a selection of rhodium-based compounds might hold the key to killing tumour cells, as well as offering hope in the battle against the West Nile and yellow fever viruses.

The chemicals only become active when a specific frequency light touches them, with scientist hoping that the property will enable them to avoid the harmful side effects of typical chemotherapy.

The findings are still at an early stage but, Harry Morrison, professor of chemistry and former dean of Purdue's School of Science, said the prospects were encouraging.

"We have proven in principle that light and chemistry together can destroy tumour cells and the Sindbis virus, a member of a group of viruses that cause encephalitis, fever and arthritis," he said.

"This research offers hope that someday we may be able to replace standard chemotherapy drugs with others that are far less generally harmful to a patient's body and guarantee safe, sterile blood for transfusions.

"Our study also found the rhodium complex capable of rendering the Sindbis virus inert."

The research was published in the latest issue of Inorganic Chemistry.