Police are warning the public to be wary of a purported facial cream being sent to some local residents.

According to Waterloo Regional Police, several residents have reported receiving plastic bags containing a “brown paste-like substance,” instructions on how to apply the alleged facial cream and the logo of Gina’s Spa.

Over the weekend, several packages of the substance were delivered to homes in Waterloo’s Beechwood West neighbourhood.

Gina’s Spa owner Jenny Decicco says she first learned of the mysterious packages Monday, when a client of the salon called to ask about it.

The package was brought into the spa for a closer look, and Decicco says she was “alarmed” by what she then saw.

“It was not very professionally packaged, and I had no idea what it was,” she said.

In addition to bearing the name and logo of Gina’s Spa, the product claims to have been created by University of Waterloo students, and includes instructions on how to apply it – specifically, with a paintbrush.

“They went to a lot of trouble,” Decicco said.

Authorities are aware of one case in which the product was applied to skin – creating a brown stain which had to be scrubbed off.

Sandra Pearen received one of the packages on her doorstep.

“I just set it aside and thought it was not very professional for Gina,” she said Wednesday.

Another package went to the home of Nadine Eby, where her son found it and passed it along.

“It did look really odd,” she said.

“It just looked like mud – like regular mud … so I was a little skeptical of it.”

Police say most of the people who they’ve talked to about the product disposed of it without giving it another thought.

The investigation into exactly what the substance is and where it comes from continues, and police say they want to hear from anyone with information.