Online travel booking site Priceline announced today that CEO Darren Huston — who has served in that role since January 2014 — will be resigning after a company investigation discovered he was in a relationship with a fellow employee.

The resignation is effective immediately, Priceline said in a statement today. While Priceline looks for a replacement, former CEO and current board chairman Jeffery H. Boyd will serve as Interim Chief Executive Officer and President of the company. He was also the CEO of Booking.com, and will be replaced in that position by Gillian Tans, the division’s operating officer since September 2011, and its president since January 2015.

Husto, who had served as CEO since January 2014, stepped down after an in-house investigation conducted by independent board members uncovered a personal relationship he had with another employee, who was not under his direct supervision, the company said in a statement.

“The investigation determined that Mr. Huston had acted contrary to the company’s code of conduct and had engaged in activities inconsistent with the board’s expectations for executive conduct, which Mr. Huston acknowledged and for which he expressed regret,” Priceline said in a statement.

Huston’s resignation “was not related in any way to the company’s operational performance or financial condition,” a company spokesman told USA Today.