British farmers and growers have been warned to avoid mysterious packages of seeds that are being sent through the post around the world.
The unsolicited packets, many of which originated from China, have created extensive suspicion and conspiracy theories.
Hundreds of people in countries such as the US, UK, Portugal, Taiwan and Holland have received the packages.
According to reports, there have been about 100 reports of people receiving them in England alone.
The UK's Animal and Plant Health Agency (APHA) has warned recipients not to plant the seeds as they could be invasive species.
The United States Department of Agriculture (USDA) has raised concern over the possibility of damage to American crops.
Osama El-Lissy, a member of the USDA's Animal and Plant Health Inspection Service said: "We have identified 14 different species... like mint, sage, rosemary, lavender, and then other seeds like hibiscus and roses."
Robin Pruisner, the state seed control official at the Department of Agriculture and Land Stewardship in Iowa, told Reuters that some packages have indicated purple seed coatings.
Recipients and authorities have shared images showing parcels marked with Chinese characters or “China Post” and as containing “rose stud” earrings.
The USDA said the mystery packages could be related to a ‘brushing scam’ - a deception sometimes used by online sellers as a way of advancing their own business.
APHA said it was currently investigating the packages in the UK: “Biosecurity is of vital importance", a spokesperson said.
"We have robust checks in place to protect our plants and wildlife, including for online plant sales.
"We are currently investigating packages of seeds marked as ‘ear studs’ sent to people in the UK.
"Anyone who has received such seeds should not plant them and instead report them to us.”
Anyone who receives unsolicited seed packages are being asked to email PlantHealth.Info@apha.gov.uk.
