AN OXFORD University scientist has signed a open letter calling for the Rio Olympics to be postponed or moved because of the Zika virus outbreak.

Dr Thuy Le, a tropical medicine expert based in Ho Chi Minh City in Vietnam, was among more than 100 leading scientists who wrote to the World Health Organisation about the crisis.

The scientists said it would be "unethical" for the Games to proceed given the side effects of the virus, including babies being born with microcephaly, or abnormally small heads.