D.C. Attorney General Karl Racine is suing Amazon, alleging the online retail juggernaut is violating city law by stifling competition and artificially raising prices for customers.

More than two million people sell products as third-party sellers on Amazon Marketplace. According to the lawsuit filed Tuesday in D.C. Superior Court, Amazon prevents those retailers from selling their products anywhere else online at a lower cost, leading to higher prices for District residents.

“Amazon has used its dominant position in the online retail market to win at all costs. It maximizes its profits at the expense of third-party sellers and consumers,” Racine said in a statement. “We filed this antitrust lawsuit to put an end to Amazon’s illegal control of prices across the online retail market.”

A spokesperson for Amazon said in a statement that Racine “has it exactly backwards.”

“Sellers set their own prices for the products they offer in our store,” the statement said. “Amazon takes pride in the fact that we offer low prices across the broadest selection.”

But Racine said Amazon’s tactics have monopolized online retail and led to fewer choices for consumers, which is prohibited by D.C. law.

Amazon requires its third-party sellers to sign an agreement promising not to sell their merchandise on other websites at lower costs, including retailers’ own websites, according to the lawsuit. Retailers that fail to do that could be banned from doing business on Amazon, which could lead to “devastating economic consequences” given its ubiquity, according to the lawsuit.

Third-party sellers must also incorporate Amazon’s high fees into the products they are selling, artificially inflating prices, Racine alleges. The lawsuit said those fees are generally higher than at other online stores, including Walmart and eBay.

Racine is asking the D.C. Superior Court to bar Amazon from engaging in anticompetitive practices and to appoint a corporate monitor to oversee any court-mandated changes to the company’s policies.