Farmers are being warned against using bucket attachments of telehandlers to drive in fencing posts.
The UK's Health and Safety Executive (HSE) says it will not hesitate to take action against those who "blatantly ignore" safety guidance.
The warning follows a rise in the number of incidents where buckets have detached from the main telescopic arm upon impact with a post, and struck people underneath.
In May, a farm worker in central Scotland badly injured his leg when he was struck by a falling bucket, while two people were killed in separate incidents less than three weeks apart in North Yorkshire last September.
HSE inspector Jean Edgar who is investigating the latest incident in Scotland says farm machinery should only be used for its intended purpose.
"Misusing equipment like telehandlers can lead to terrible tragedy," she says. "Where HSE identifies dangerous working practices like this, where safety guidance is blatantly ignored, we will not hesitate to take enforcement action."
HSE is Britain's national regulator for workplace health and safety. It aims to prevent death, injury and ill health through research, information and advice; promoting training, new or revised regulations; and working with local authority partners. Information on the safe use of agricultural machinery can be found at www.hse.gov.uk/agriculture