Several Australian road workers were sent for medical treatment after they vomited when suspected nuclear material was unearthed during a New South Wales highway upgrade.
The materials were buried near Laurieton, south of Port Macquarie, after a truck carrying radioactive elements including caesium and americium crashed in 1980.
The isotopes were being taken from a nuclear reactor in Sydney to Brisbane, from where it was due to be shipped to the United States.
Road upgrade project manager Bob Higgins says the workers fell ill after unearthing a strange clay-like material from a cutting where material from the crash is believed to have been buried.
None of the workers is believed to have been poisoned.