Just a few years ago, the hottest holiday toy was the Hoverboard, the self-balancing scooter that creates an illusion of floating through air.

But the brand-name device was pricey, so many people turned to the Internet for knockoffs.

"We saw a real demand for the Hoverboard, which when it came out was very expensive," recalled Philadelphia City Councilman Derek Green. "As we got into the beginning of the year, we began learning of all these incidents with [fake] Hoverboards that caught on fire and caused damage to households across the country" because people purchased the lower-quality versions online at a steep discount.

On Tuesday, Green and the consumer watchdog group PennPIRG appeared at City Hall to advise the public about this year's crop of toys that may pose a threat to children's health.

"Trouble in Toyland," a new report by the U.S. Public Interest Research Group Education Fund, warns about toys that may still be available for sale online despite being recalled by their manufacturers. The toys may pose choking hazards, overheat because of poorly manufactured batteries, or contain lead paint.

Examples include a beanbag chair recalled in 2015 after two children opened the zipper, crawled inside and suffocated. It's still available for sale online, said PennPIRG Field Director Michael Roles. U.S. PIRG is the national organization.

Another example of a potentially hazardous toy was a "monkey glockenspiel," a xylophone-style instrument that was recalled by the manufacturer in February when lead paint was found on a pink-colored key.

"We all thought lead was out of our toys," said Roles. "Don't trust that they are safe just because they are available for sale."

Roles urged consumers to check the Consumer Product Safety Commission's online database of recalled toys if they have any concerns about new products.

"In the '70s, '80s early '90s, if a toy was recalled, you wouldn't have been able to buy it, because a store would take it off the shelf," Green said. "Now in the Internet age people have that construct that if something is for sale, it must be safe."

Green pointed out the lead paint on the glockenspiel as a particularly shocking item.

"I can be making sure my house is repainted, looking for paint chips, changing the pipes to make sure no lead is leaking into my water," he said. "But then lead gets brought into the household through a gift that a grandparent bought, not knowing that the paint has lead that could rub off. I think this is something that it is important for parents to know."