Language experts are employed to analyse "snippets" of recordings made by users, which Google claims helps improve its voice recognition technology.
This is then used to develop the Google Assistant artificial intelligence system, which is used in its Google Home smart speakers and Android smartphones.
The assistant understands and responds to voice commands given to it, answering queries about the news and weather as well as being able to control other internet-connected devices around the home.
In a statement, the company said a small number of anonymous recordings were transcribed by its experts, and revealed that an investigation had been launched after some Dutch audio data had been leaked.
"We partner with language experts around the world to improve speech technology by transcribing a small set of queries -- this work is critical to developing technology that powers products like the Google Assistant," Google said.
Language experts only review around 0.2% of all audio snippets, and these snippets are not associated with user accounts as part of the review process.--INDEPENDENT