Politicians and patients have raised privacy concerns over Google’s access to millions of individual medical records.

A United States federal regulator has initiated an investigation into a cloud computing deal between Alphabet Inc’s Google and Ascension Health, which would give Google access to detailed health information of millions of patients, the Wall Street Journal (WSJ) newspaper reported.

The Office for Civil Rights in the Department of Health and Human Services will look into the data collection to ensure the partnership is in compliance with the Health Insurance Portability and Accountability Act, which safeguards medical information, the WSJ quoted the office’s director, Roger Severino, as saying.

“We are happy to cooperate with any questions about the project,” Google said in a blog post later on Tuesday, regarding the federal inquiry.

Representatives of the health and human services department did not respond to a request for comment, Bloomberg reported.

However, Google’s top health and cloud executives have pushed back against criticism over privacy issues from US lawmakers and patients, saying that the company is not misusing data from one of the biggest healthcare providers in the US.

Google employees only have access to patient information in order to build a new internal search tool for the Ascension hospital network, said David Feinberg, head of Google Health in a Bloomberg report.

No patient data is being used for Google’s artificial intelligence research, he added.

The company is governed by US health privacy law that permits access to patient records only for the task of organising Ascension’s various health record systems and building a tool to make them easier to search, Feinberg said.

“That’s all we’re allowed to do and that’s all we are doing,” he said.

On Monday, Google said patient data “cannot and will not be combined with any Google consumer data.”

Ascension’s health data is being stored on Google Cloud servers but sequestered so only Ascension employees can access it, according to Google.

“All data is logically silo-ed to Ascension and housed within a virtual private space encrypted with dedicated keys,” Kurian said. “Google does not sell, share or otherwise combine data from Ascension with any other data.”

Under the agreement with St Louis-based Ascension announced on Monday, Google would gain access to the data of about 50 million patients. The deal has come under heavy scrutiny ever since the WSJ reported that identifiable data was being collected that could be used to build new products.

According to Feinberg, Google’s health team is currently building a tool that can help to make it easier for doctors and nurses to find the exact data they need when they need it by scanning through Ascension’s multiple electronic health record systems.

The project is still in its infancy, but could eventually become a standalone product that Google could sell to other healthcare providers and entities, Feinberg said.

“If we can help solve the information overload and the pressures on doctors and nurses then there would be a huge benefit to a lot of people in those types of tools,” he said. “To me, that is actually really, really exciting.”

Ascension has more than 2,600 facilities like hospitals and nursing homes in 21 states and Washington, DC. Neither doctors nor patients have been formally notified of the arrangement, WSJ reported.