It seemed like an innocent mix-up when the first two Amazon Prime packages containing cookie cutters and nail clippers showed up for Molly Schoenecker last month at her parents’ Bloomington home.

“I was like, ‘This is a mistake — I didn’t order this,’ ” said the University of Minnesota senior. “I didn’t think much of it at first. I thought it was kind of funny.”

The next day, two more packages arrived, this time with sweatshirts and a cable adapter inside. There was no receipt or invoice — and no hint of who the sender may be.

But they weren’t laughing when they discovered what was inside the next anonymously sent package.

“This one is bad,” her mother, Liz Schoenecker, told her on the phone after opening it. It had a sex toy in it.

Molly Schoenecker was creeped out, too. So they called the police.

“It was terrifying to us that it was someone stalking her,” her mother said. “We were panicky.”

In all, the Schoeneckers have received about 24 packages from Amazon that they didn’t order over the course of the last month.

In recent weeks, a handful of other stories about people receiving mysterious packages from Amazon have begun to surface across North America. A retired couple outside of Boston reported receiving at least 25 packages that contained plastic fans, phone chargers and other eclectic items. They were told by Amazon that the packages were bought with a gift card with no sender’s name or address. In Canada, several college student unions have received anonymous packages containing random items including sex toys and light bulbs.

“We are investigating inquiries from consumers who have received unsolicited packages as this would violate our policies,” Amazon said in a statement. “We have confirmed the sellers involved did not receive names or shipping addresses from Amazon.”

A recent Daily Beast story cited an unnamed Amazon source saying that the company has been baffled about why this is happening and that many of the cases seem to include sex toys.

Some experts have conjectured that the people sending the packages could be trying to exploit Amazon’s review system by being able to show they made a “verified purchase” of that item to improve its ranking on the site when writing a glowing, fake review of it.

But Amazon said it not does not believe abusing customer reviews is the motivation in these cases since it has found “very few” reviews written on these unsolicited shipments. The company added that it immediately removes any such reviews when it finds them.

Will Tjernlund, managing partner of Goat Consulting, a Minneapolis-based firm that helps third-party vendors sell products on Amazon’s marketplace, is also skeptical that this has to do with fake reviews.

Rather, he thinks the mysterious deliveries could involve sellers who are trying to game Amazon’s search results in a different way: by increasing sales.

He said Amazon’s algorithms will push products to the top of search results that have high sales and high conversion rates.

“People like to focus on the reviews because it’s an easy thing to visualize,” said Tjernlund. “But I think they’re trying to get the sale, first and foremost. If Amazon sees a product with [a lot of] sales, they will push it to the top.”

The Schoeneckers were relieved when they started seeing news stories about others receiving unsolicited packages, and the possible explanations.

When the deliveries first started, Molly Schoenecker called Amazon’s customer service to try to get to the bottom of it. She was told the packages had been sent by a man whose name she did not recognize. They also gave her his e-mail address.

“They said it was sent as gifts,” she said. “They said just throw them away if you don’t want them.”

She sent an e-mail to the sender saying she wasn’t sure if this was a mistake, but she was receiving these packages and didn’t want them. She never received a response. Schoenecker searched the person’s name on the internet and found several people with that name on Facebook, none of whom seemed to be in Minnesota.

But she wondered if it was an alias since the e-mail address had random letters and numbers after it.

Once the sex toy arrived, Schoenecker became more nervous about how the person had found her address. She has a student Amazon Prime account and would sometimes send packages to her parents’ house instead of to her apartment near campus.

So she called Amazon again and asked to speak to a supervisor this time, saying the situation was getting scarier. She spent nearly two hours on the phone and was told that they would refer her case to a team that handles such situations and that would get in touch with her within 48 hours.

“I never heard back from them,” she said. “It was frustrating because it’s such a big company and I felt like I was in a situation where I felt kind of threatened by this and I’d like some help.”

Next, they turned to the police. Bloomington police took pictures of the shipping labels. But they couldn’t find anyone living in Minnesota with the name the sender had used, according to the police report. Deputy Chief Mike Hartley said in an e-mail that he can’t comment on the case since it’s still active

In the meantime, more shipments from Amazon continued to arrive on the Schoeneckers’ doorstep. HDTV antennas, a shower head with a Bluetooth speaker, a keyboard case for an iPad, a portable fan, a hair straightener, a blue dress, an essential oils diffuser, baby booties. And another sex toy.

Some days, several packages arrived. One day, Liz Schoenecker came home to find three packages. Later that night, she got a text from a neighbor saying there were two more boxes outside.

“They probably think we have a shopping addiction,” she quipped.

There was a lull in the deliveries in the last week. They hope that means the deluge of packages has finally stopped and they can move on.

They got rid of the boxes and are planning to donate all the items.