More than a year after Mark Hayes' name arose in an insider trading investigation, the Greenberg Traurig life sciences and health care partner has left the firm's office in Washington, D.C., to start his own practice.

Hayes, a former congressional aide for four U.S. senators hired by Greenberg Traurig in November 2010, formed Hayes Health Policy Strategies earlier this month. He did not immediately return a request for comment about his decision to leave Greenberg Traurig to start his own lobbying shop in suburban Annandale, Virginia.

In April 2013, while at Greenberg Traurig, Hayes sent messages to a political intelligence and research firm called Height Securities predicting a change in Medicare policy that sparked a surge in Wall Street trading on health care insurance stocks, according to a report at the time by sibling publication Legal Times. The purported tip led health care giant Humana to terminate its client relationship with Greenberg Traurig, while Hayes was placed on leave by the firm.