A federal inquiry has been opened in regard to this matter
Google has gained access to a huge trove of US patient data, without notifying those patients, through a deal with a major health firm.
Ascension, one of the country's largest nonprofit and Catholic health systems, agreed with the scheme named Project Nightingale and hopes to develop artificial intelligence tools for doctors.
The tech giant reportedly has access to health records, lab results, diagnoses, records of hospitalization, dates of birth, names and addresses of patients, reports the Wall Street Journal.
Google said it was "standard practice."
Neither doctors nor patients need to be told that Google can see this information. The data access began last year and was broadened over the summer.
A federal inquiry has been opened against Google's Project Nightingale program, the report added.
The Department of Health and Human Services' Office for Civil Rights opened the inquiry on Tuesday.
In a statement to the publication, the office Director Roger Severino said: "We 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] protections were fully implemented."
In a blog, Google said its work with Ascension would adhere to industry-wide regulations, such as the US HIPAA.
"To be clear... patient data cannot and will not be combined with any Google consumer data," the firm added.
Ascension, which runs 2,600 hospitals, said the deal would help it to "optimize" patient care and would include the development of artificial intelligence (AI) tools to support doctors.
The company also said it would begin using Google's cloud data storage service and business applications known as G Suite, reports BBC.
However, Project Nightingale has already attracted criticism from those who argue that it takes away patients' control of their own data.
University of Oxford Prof Jane Kaye said "There's a massive issue that these public-private partnerships are all done under private contracts, so it's quite difficult to get some transparency.
"Google is saying they don't link it to their other data but what they're doing all the time is refining their algorithms, refining what they do and giving them[selves] market advantage."
Google's push into health care comes amid growing interest in the space from tech companies, such as Apple, Amazon and Microsoft. All three companies have launched initiatives to modernize the US health care system in recent years.