Fury as it emerges Google is working on a top secret project with access to millions of Americans' health data including lab tests and diagnoses - but patients and doctors have not been told

Google has been working on a top secret project with a leading healthcare company to gather millions of Americans' health data without them knowing it. 

The Wall Street Journal first reported on Monday that the company has teamed up with Ascension, the second largest healthcare services company in the country, for a project that was being code-named Nightingale. 

Within hours of the Journal's report, the two companies announced the collaboration in a press release where they revealed that Ascension's data will move onto Google's Cloud platform.  

Google will now have access to patients' test results, diagnoses and hospitalizations to give them a full digital health history. 

Neither doctors nor the patients in the 21 states where it will be used had been told about it. 

As many as 150 Google employees have already seen some people's data, it is reported. 

They and employees at Ascension have voiced concerns over the way it has been harvested, despite it being legal. 

According to the Journal's report, Google is using the information to inform new design software that will rely heavily on artificial intelligence. 

Its purpose will be to 'zero in on individual patients to suggest changes to their care.'

A Google spokesperson said the project is legal.

But the company did not immediately respond when asked specifically by DailyMail.com how the data will be used or why the company did not inform patients or doctors about it being accessed.

Ascension did not answer specific questions about the inner-workings of the deal or how much data was being sold for. 

When contacted, the company referred to a press release in which it touted the pairing as a 'collaboration' designed to 'optimize the health and wellness of individuals and communities, and deliver a comprehensive portfolio of digital capabilities that enhance the experience of Ascension consumers, patients and clinical providers across the continuum of care.'  

At the end of the release, the company said: 'All work related to Ascension’s engagement with Google is HIPAA compliant and underpinned by a robust data security and protection effort and adherence to Ascension’s strict requirements for data handling.'

The practice is legal under the Health Insurance Portability and Accountability Act of 1996 which allows hospitals to share patients' medical data with business partners on the condition that it is used to 'help the entity carry out its healthcare functions.'