“We’ve received reports and detectives are finding out whether it’s in violation of telecommunications law,” Hamburg police spokesperson Ulrike Sweden told the Hamburger Morgenpost.

The white mini-radio, about the size of two matchbooks, comes with issue 12 of the €3.20 Micky Maus comic book released on Monday, and officers have picked up several of the radios from newsstands to conduct tests.

Concerned parents in Hannover have also notified authorities that their children were picking up police chatter on the radios, which look similar to iPods. But a Hannover police spokesperson told the paper that officials believe they are dealing with a limited problem.

The comic book publisher Ehapa Verlag spokesperson Elke Schickedanz told the paper that the radio, manufactured in China, was “scrupulously tested at an institute for toy safety” and should only be able to tune into normal radio stations.

A statement on the publisher’s website assured readers on Friday that media reports are of “isolated cases.”

“Hence our request to Mickey Mouse readers: The radio is exclusively designed for listening to music. Everything else is not allowed,” the statement said.