Amazon claimed federal investigators have mounted a campaign to “harass” top executives including founder Jeff Bezos as part of a probe into alleged antitrust violations by the e-commerce giant that suffered a mysterious, six-month “breakdown” several months ago.

The Seattle-based company alleges that the Federal Trade Commission is issuing subpoenas for Bezos, current CEO Andy Jassy, and nearly two dozen other former and current employees and executives that are “unduly burdensome, and calculated to serve no other purpose than to harass Amazon’s highest-ranking executives and disrupt its business operations.”

Amazon’s legal filing also alleges there was an unexplained “breakdown” in the FTC’s investigation that began late last year, claiming that the agency’s investigators went radio silent for six months after it provided more than 37,000 pages of documents.