Student union officials at a number of Canadian universities have been baffled by the delivery of anonymous packages containing sex toys.

Representatives at 10 campuses across the country have been sent up to 15 packages each since November, containing goods valued at around CN$1,000 (£521). The parcels contained phone chargers, mobile phones, lightbulbs and adult toys.

According to Mounted Police constable Darryl Waruk, detectives have failed to identify the sender but said the packages could be the result of a marketing ploy by a company in China.

Amazon, which delivered the goods, said it could not reveal the identity of the purchasers because of its privacy policy. Students could not return the items because they were bought by a third party, Amazon added. It is thought that at least some of the items were bought using gift cards.

The University of Manitoba in Winnepeg said it was auctioning off the items to help support LGBT groups on campus.

Ryerson Students' Union president Susanne Nyaga said that she and fellow student members wanted an end to the deliveries.

"If this is a prank — good job it happened. This is a lot of money you're investing in a prank," she said.

"At this point I have no idea what this could be, it's like a never-ending prank and someone just has all this money. I just have no idea what the source of this is at all."