A poison pen letter with a difference has been sent to the Southern District Health Board - a sample of material possibly containing asbestos.
The unwanted delivery has prompted a warning from health officials for people not to handle hazardous materials themselves, but to call in a health protection officer first.
That precaution was not taken by the correspondent, who instead opted to send the potentially deadly material by mail to the DHB for testing.
''We appreciate that people are trying to do the right thing by getting asbestos tested,'' DHB medical officer of health Marion Poore said.
''But we need to take precautions to protect the health and safety of our staff and community.''
WorkSafe New Zealand was notified of the incident, but a spokesman said the incident did not meet its criteria for further investigation.
Asbestos was a commonly used building material but is now known to cause a wide range of serious health issues, including deadly illnesses.
Unsuspecting homeowners run the risk of exposure to asbestos when disturbing or removing building materials.
''It is important to seek advice from a health protection officer prior to collecting samples to help ensure any samples are collected and submitted safely,'' Dr Poore said.
The Southern DHB website page on asbestos now has a warning in bold type not to send asbestos samples in the post.
Health protection officers are available to provide advice in Otago and Southland.
Professionals such as builders, roofers and flooring companies are expected to remove samples in accordance with Worksafe guidelines and submit them to a lab for testing.
