The Google Home Mini Google A coalition of privacy advocacy groups are urging federal regulators to recall Google's new $50 smart speaker, after a malfunction in some early units caused it to secretly record conversations.

The Google Home Mini has not actually shipped yet — the device is slated to go on sale October 19 — but product reviewers at various media organizations have had early access to evaluation units for weeks. One reviewer from Android Police reported that a glitch in his device's touchpad caused the puck-shaped to record everything he said, rather than only when activated.

The glitch "allowed Google to intercept and record private conversations in homes without the knowledge or consent of the consumer," reads a letter to the head of the US Consumer Product Safety Commission on Friday, signed by 10 consumer and privacy advocacy groups.

"It is important to underscore that the failure of the Google device stems from the design of the “touchpad.” There is no simple solution that will restore the correct functionality of the device," the letter continues.

The Home Mini device was designed to be activated by a user saying "Ok Google" or by touching a small button on the top. Once activated, the device listens to a user's voice and responds to requests such as queries about the weather, musical selections and other information.

Google said it only received "a few reports" of the glitch. But the internet company rolled out a software update earlier this week that completely disabled the button on all of its Home Mini devices.

The incident is an embarrassing setback for Google as it seeks to establish itself as a leader in the emerging and competitive market for smart-speakers, in competition with Amazon, Apple and Facebook. It means Google will essentially be coming to market with a product that has been partially disabled.

And the glitch could heighten consumer distrust of Google, which has a history of privacy missteps.

The flaw was due to a glitch in the Mini's button that caused it to detect a touch even when there was not touch to detect. The Android Police reviewer discovered the problem after checking his personal activity page on Google's website and seeing that files had been uploaded to Google's servers from the Mini without his knowledge.

The Electronic Privacy Information Center, the Center for Digital Democracy and Public Citizen were among the groups that signed the letter.