The attorneys general of New York and California will investigate the market dominance of Amazon and its online marketplace in partnership with the FTC.

The three agencies will be working together to interview witnesses on joint conference calls in the coming weeks, according to a report by Bloomberg.

Diana Moss, the president of the American Antitrust Institute, said that when state and federal regulators work together, it can oftentimes result in a large antitrust action — similar to the one that was taken against Microsoft.

“This appears to be taking the shape of what could be a major collaborative antitrust investigation,” said Moss. “This happens in big cases where the feds have a stake in enforcing the law, and also when states have an interest in protecting their constituents.”

The report added that New York Attorney General Letitia James is also investigating the termination of Chris Smalls, an employee who led a protest at an Amazon warehouse in Staten Island. Amazon said Smalls, as well as three other activist workers who were fired for violating company policy.

The company has fallen under scrutiny in the past for its allegedly bad workplace conditions.

Last year, injured former Amazon warehouse workers and labor organizers protested the dangerous work speeds and high injury rates at Amazon’s automated warehouses at the company’s brick-and-mortar stores in downtown Chicago.

In April, Amazon fired at least two programmers after they voiced public criticisms of workplace conditions at the company’s warehouses.

Now, Amazon is also being scrutinized for allegedly abusing its online market power, reports Bloomberg, adding that the company’s Jeff Bezos testified last week before a House committee probing antitrust allegations alongside the chief executives of Google, Facebook, and Apple.

The report added that almost 40 cents of every dollar spent online in the United States goes to Amazon, and that the company has more of the online retail market than its nine biggest competitors combined, which include Walmart and EBay, according to EMarketer.

Meanwhile, Amazon insists that it represents a small fraction of total U.S. retail sales.

You can follow Alana Mastrangelo on Twitter at @ARmastrangelo, on Parler at @alana, and on Instagram.