Australia's air safety body is looking into reports that a triathlete has been injured by a falling drone.
Raija Ogden reportedly sustained minor head injuries after the drone's operator lost control of the device.
The videographer operating the drone claimed the craft had crashed because an attacker managed to wrest control away from him.
The drone was being used to film competitors in the Geraldton Endure Batavia triathlon in western Australia.
Ms Ogden was treated at the scene of the accident before being taken to hospital where stitches were required to close a head wound.
The drone was being piloted by local photographer Warren Abrams who set it hovering about 10m above the race route to capture images of competitors completing the 10km run section of the triathlon.
Geraldton Triathlon club has apologised to Ms Ogden who was only metres away from the finishing line when she sustained her injuries.
Conflicting reports about the incident have emerged in local media. Some witnesses said the drone fell directly on to Ms Ogden but others said she tripped and fell after being startled by the plummeting device.
Mr Abrams told ABC news that video footage shot by the drone clearly showed it missed Ms Ogden and fell just behind her. In later reports Ms Ogden disputed this version of events saying she only sat down as she thought she was going to faint after the craft hit her.
The incident is now being investigated by Australia's Civil Aviation Safety Authority whose rules dictate that unmanned aircraft must fly a minimum of 30m away from people. Operators of drones are required to be certified by the agency to fly the unmanned craft.
The Agency is now looking into the incident as news reports raised questions about whether Mr Abrams was certified to operate the drone.
Mr Abrams said his initial investigation suggested that he lost control after someone else briefly took over flying the drone. Determining who in the crowd of competitors had stolen control would be tricky, he said, because smartphones could easily be used to carry out such an attack.