Two US lawmakers spearheading an antitrust investigation into Amazon are looking into whether a top company official lied before Congress about whether the e-commerce giant uses independent seller data to create its own products and unfairly compete on its platform.

In a report Thursday, the Wall Street Journal wrote that Amazon employees used independent seller data to develop the company’s own competing products. In one case, Amazon employees allegedly analyzed the sales and profit margins of a car-trunk organizer created by a third-party seller, using it to make a decision about launching a directly competing product.

Over the last few months, the House Judiciary Committee has been engaged in an antitrust investigation looking into Big Tech companies, including Amazon. The two lawmakers at the forefront of that probe, Reps. Jerry Nadler (D-NY) and David Cicilline (D-RI), put out statements responding to the Journal calling on Amazon to clarify previous statements made to the committee that appear to contradict the report’s findings.

“It is deeply concerning that, beginning with the hearing last year, they may have misled Congress rather than be fully forthcoming on this matter, notwithstanding our repeated requests in this regard,” Nadler said in a statement.

“At worst, the witness Amazon sent to speak on its behalf may have lied to Congress.”

“At best, Amazon’s witness appears to have misrepresented key aspects of Amazon’s business practices while omitting important details in response to pointed questioning,” Cicilline said Thursday. “At worst, the witness Amazon sent to speak on its behalf may have lied to Congress.”

Earlier on Thursday, Amazon responded to the Journal’s report saying that the company looks “at sales and store data to provide our customers with the best possible experience.” Still, the company claimed that it “strictly” prohibits employees from “using non-public, seller-specific data to determine which private label products to launch.”

Later, Amazon responded to the lawmakers’ calls for clarification and announced that it was investigating these claims internally “It’s simply incorrect to say that Amazon was intentionally misleading in our testimony,” a company spokesperson told The Verge. “While we don’t believe these claims made by the Wall Street Journal are accurate, we take these allegations very seriously and have launched an internal investigation.”

At a July 16th hearing before the House Judiciary Committee, Amazon’s associate general counsel Nate Sutton said that the company does not access seller sales data to develop its own products. “Our incentive is to help the seller succeed because we rely on them,” Sutton said.

Amazon told the Journal that any employees accessing independent seller data to create the company’s own competing products would violate its policies, but it’s not clear how Amazon enforces that policy or what safeguards it has in place to prevent employees from accessing it.

The House Judiciary Committee initially planned to release its findings from its Big Tech antitrust investigation last month, but the novel coronavirus pandemic appears to have delayed the final report. It’s not clear when the committee will go public with its findings.

“We plan to seek clarification from Amazon in short order, in light of this troubling report,” Nadler said in a statement to Recode Thursday.