When Jeff Bezos testified in an antitrust hearing in front of the US House of Representatives last year, he probably thought that the worst came to pass. In that historic hearing, Bezos reiterated that Amazon (AMZN) never violated antitrust policies. A little more than a year has passed since that day, and Amazon is once again in hot waters.

A joint report published by Reuters and Markup last week presented the case that Amazon uses the data of third-party sellers on its platform to inform and create its private-label products. On top of that, the report also explained how Amazon prioritizes its own products in searches.

The report wasn't created out of thin air — it was based on thousands of internal Amazon documents collected and analyzed by the two publications. Lawmakers have now sent a letter to Amazon giving the company one last chance to corroborate its prior testimony and admit its wrongdoings.