The research follows a study by a team in Pittsburgh, USA, published earlier this year which found no evidence that the drug posed an increased risk of heart disease.

BBC: Cancer wonderdrug 'may protect heart'

The study, published in the journal "Proceedings of the National Academy of Sciences of the USA, " suggests that the number of amphibian species in Madagascar has been significantly underestimated.

CNN: Hundreds of new frog species found in Madagascar