Several US senators are asking Amazon for more information about its Echo Dot Kids Edition, which advocacy groups claim violates kids' digital privacy.

The smart speaker will allegedly keep a child's recorded data even after parents try to delete it via the Alexa app, according to the Campaign for a Commercial-Free Childhood and the Center for Digital Democracy. To truly delete the information, you'll have to call up Amazon's customer support.

Another big problem includes Amazon's failure to fully disclose what information the device can collect from the child and how it's used, the groups claim.

"We spent months analyzing the Echo Dot Kids and the device's myriad privacy policies and we still don't have a clear picture of what data is collected by Amazon and who has access to it," Angela Campbell, a board member with the Commercial-Free Childhood group, said in a statement.

The findings prompted four US senators to ask the Federal Trade Commission to investigate whether Amazon is violating the Children's Online Privacy Protection Act (COPPA). The law requires vendors to give parents access to their child's personal information, and the ability to delete it. The vendors' data-collection practices must also be posted clearly in an online privacy policy.

"Voice recognition technology and artificial intelligence tools such as the Echo Dot Kids Edition have the potential to enrich and educate kids, including through music and storytelling. But these devices also present significant privacy concerns," reads a letter to FTC signed by Democratic Sens. Edward Markey, Richard Blumenthal, and Dick Durbin, as well as Sen. Josh Hawley, a Missouri Republican.

Amazon says its products are fully compliant with COPPA. It did not respond to questions about why the Echo Dot Kids product can fail to delete a child's data, as the advocacy groups have charged. So it isn't clear if this was a bug, delay with the Alexa app, or something else.

The senators, meanwhile, take issue with how Amazon's privacy policy for kids often uses the phrase "may collect," as opposed to stating what it actually collects.

This comes after Bloomberg reported that Amazon employs thousands of people to listen to saved voice recordings made with Alexa-powered smart speakers. The company does this to help improve the voice assistant technology, but the practice can end up exposing snippets of private conservations made by users.

Voice recording happens by default. To stop it, you'll have to go to the Alexa Privacy setting, and opt out.

This article originally appeared on PCMag.com.