The first Amazon deal made under new CEO Andy Jassy is getting Federal Trade Commission scrutiny.
In question is Amazon’s $3.9 billion acquisition of the primary health organization One Medical.
The investigation could delay the completion of the deal.
A request for additional information was received by both One Medical and Amazon on Friday in connection with an FTC review of the merger, according to a filing made with securities regulators by One Medical's parent, San Francisco-based 1Life Healthcare Inc.
In recent years, Amazon has been making a push into health care.
It purchased acquisition of the online pharmacy PillPack for $750 million in 2018.
Amazon announced plans in late July to buy One Medical, a concierge-type medical service with roughly 190 medical offices in 25 markets.
Last week, the e-commerce giant said it would shut down its own hybrid virtual in-home care service called Amazon Care, a One Medical competitor, because it wasn’t meeting customers' needs.
Groups calling for stricter antitrust regulations quickly urged the FTC to block the One Medical merger, arguing it would further expand the company’s massive market power.
An Amazon spokesperson declined to comment.
The FTC has already been investigating the sign-up and cancellation practices of Amazon Prime and has issued civil subpoenas in that case.
The Associated Press contributed to this report.