Someone call Sherlock Holmes because there's a mystery in Canada that needs solving; unsolicited packages of seeds sent from places such as China keep showing up in people's mail and it's unclear exactly who's sending them.

The Canadian Food Inspection Agency (CFIA) sent out a tweet on July 28 reminding Canadians not to plant the seeds.

"Unauthorized seeds could be the seeds of invasive plants, or carry plant pests, which can be harmful when introduced into Canada," the CFIA said in a statement.

"These species can invade agricultural and natural areas, causing serious damage to our plant resources."

Did you receive unsolicited seeds? Contact your regional CFIA office right away: https://t.co/9A0cleZUvW. We are investigating. Do not plant the seeds! Learn more: https://t.co/cKHYz7Cqnn pic.twitter.com/DnDIkCXeNs

— Canadian Food Inspection Agency (@InspectionCan) July 29, 2020

The Ontario Provincial Police also put out a warning in response to the incidents, urging Canadians not to plant the seeds.

"If you receive an unsolicited shipment of foreign seeds in the mail from China or Taiwan DO NOT plant or dispose of them," the police force said in a recent tweet.

If you do happen to be sent a package of seeds that you weren't expecting, police remind you to contact the CFIA.

And it seems that it isn't just a Canadian problem; our neighbours south of the border have also been receiving unsolicited packages of seeds, with 27 states issuing warnings about seed packets from China as of earlier this week.

We have received reports of people receiving seeds from China that they did not order. If you receive them - don't plant them. Report to @USDA_APHIS at https://t.co/0U53rbAiHs pic.twitter.com/Y4yAKv5bk7

— WA St Dept of Agr (@WSDAgov) July 24, 2020

According to the government website, invasive alien species can cause significant ecological and economic damage, harming biodiversity by displacing native species.

So as tempting as it is to plant the seeds, Canada, let's stick to buying our plants at Home Depot.