Security fears have been sparked after numerous cases of people around the world reported receiving mysterious 'seed packages' with unknown contents.

Thousands of shipments of seeds are said to have arrived at homes in New Zealand, the US, Canada and Europe, with 100 cases in the UK.

The origin of the seeds is unknown, and this has sparked biosecurity fears among officials.

International investigations have been launched in order to uncover the source of the seeds, as well as to determine the reason they've been posted.

What do the seeds look like?

Photographs posted by recipients show that the packaging of the seeds varies, with some packages marked as containing a "toy", others bearing Chinese characters, and some marked as "rose stud" earrings - likely in order to evade security checks.

Alarmingly, the shipments are addressed to recipients by name, suggesting that there may have been a data breach.

The US Department of Agriculture (USDA) has asked recipients of the seeds not to plant them while it works out the source and nature of them.

In the UK, the Animal and Plant Health Agency (Apha) of the Department for Environment, Food and Rural Affairs is similarly investigating reports of the seeds.

An Apha spokesperson said: “Biosecurity is of vital importance and 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.”

Where have the seeds come from?

The most likely explanation for the seeds is that they're collateral in a so-called 'brushing scam'.

A brushing scam occurs when people are sent items unsolicited by online sellers to generate a transaction and thus support fake reviews to boost their business or product.

Some officials fear that the seeds could be an invasive species, such as Japanese knotweed, intended to introduce disease, pathogens or otherwise compromise national security.

Where should any reports be made to?

Members of the public across the UK should report suspicious seeds to PlantHealth.Info@apha.gov.uk