The Department of Health and Human Services's Office for Civil Rights opened the inquiry Tuesday, The Wall Street Journal reported.
The Office "will seek to learn more information about this mass collection of individuals' medical records to ensure that [the Health Insurance Portability and Accountability Act of 1996 or HIPAA] protection is fully implemented," said Office Director Roger Severino in a statement to the publication.
The Department of Health and Human Services did not respond to CNN Business & # 39; s request for comment.
The data collection was done through a new partnership between Google ( GOOG ) and Ascension, one of the country's largest health care and non-profit organizations . The two companies confirmed that they were working together to analyze patient data and provide new insights and suggestions for patient care to healthcare professionals. The Wall Street Journal was the first to report on the project on Monday.
The Google-Ascension partnership will integrate Ascension's various areas of health data into the cloud. Google said in a blog post Monday that the project was a "business plan to help a provider with the latest technology, similar to the work we do with dozens of other healthcare professionals."
The Journal reported that at least 150 Google employees had access to patient data, but Google said they adhere to regulatory standards, such as HIPAA. Google said that Ascension's data "cannot be used for any purpose other than to provide these services we provide under the agreement, and patient data cannot and will not be combined with Google consumer data."
Shortly after the journal report was published, both companies made allegations.
Google acknowledged the sensitive nature of patient health data. Ascension, which is based in St. Louis, has 2,600 facilities in about two dozen states. It said that working with Google followed the law. But the magazine reported that some of Ascension's employees questioned how Google shares and collects patient data.
This is not the first time Google has gained control over the processing of user data.
Google paid a $ 170 million record penalty to the Federal Trade Commission for settling allegations that YouTube violated the law when it deliberately tracked and sold ads targeting children.
Google's entry into healthcare comes amid growing interest in the space from technology companies, such as Apple ( AAPL ) Amazon ( AMZN ) and Microsoft ( MSFT ) . All three companies have launched initiatives to modernize the US health care system in recent years.
CNN's Rachel Metz and Jordan Valinsky contributed to this report.