Scam alert: Fake Stanley cup sales on the rise, police warn

Heads up if you're interested in buying a sold-out Stanley cup - beware of fake tumblers! 

Authorities are warning about an uptick in counterfeit Stanley cups amid a surge in popularity over the Quenchers.

"This past summer, we found them for as cheap as $19. Sounds too good to be true? Well, it is," one police department in Illinois warned on social media.

RELATED: Starbucks pink Stanley cups: Shoppers line up at Targets at 3 a.m.

"Beware of tricky websites using the brand’s popularity. Shady websites pretending to offer discounts on Stanley cups have been found to be scamming shoppers."

The warning comes after the chaos that ensued following the releases of Stanley's limited-edition pink Valentine's Day tumblers at Target and Starbucks. 

Authorities are warning of questionable websites that are falsely advertising cheap Stanley cup tumblers for as low as $6. So if it's too good to be true, it probably is, authorities warn.

RELATED: Starbucks selling pink Stanley cups after Target sells out within minutes

Consumers are also advised not to take ads on social media at face value and to read customer reviews for additional guidance. When possible, purchase only from verified retailers.