CONCACAF has announced it has completed an investigation into the referees' performance at last summer's Gold Cup tournament, and that there was no evidence of match fixing in the wake of several controversial decisions at the event.

CONCACAF also announced that following a complete review of its referee department, it will enact a series of reforms.

"CONCACAF's referees are critical to our organization's mission, and we are proud to have dedicated officials working to ensure that the Confederation's tournaments are officiated with integrity," said CONCACAF Acting General Secretary Ted Howard.

"We are committed to making the necessary improvements to our referee department to ensure that it operates effectively. These changes will provide our referees, officials, and assessors with the proper structure, training, and support to carry out their responsibilities on the field, while acting in the best interests of the game."

At issue were decisions made during the Gold Cup quarterfinal between Mexico and Costa Rica, as well as the semifinal contested by Mexico and Panama. In both matches, the controversial decisions favored El Tri. Against Costa Rica, referee Walter Lopez of Guatemala whistled a penalty in the 120th minute against the Ticos when defender Roy Miller nudged Mexico forward Oribe Peralta, despite there being just minimal contact. Andres Guardado converted from the spot to give Mexico a 1-0 victory.

In the semifinal, Mexico prevailed 2-1 after referee Mark Geiger controversially sent off Panama forward Luis Tejada in the 25th minute, and then called two penalties in favor of El Tri, both of which were converted by Guardado. The first, in second half stoppage time, was highly contentious, and tied the match 1-1. Guardado then converted the winner in extra time.

In the aftermath, allegations of match fixing were leveled by Panamanian Football Federation president Pedro Chaluja. But CONCACAF said that its investigation uncovered no evidenced of wrongdoing.

"CONCACAF found no clear or convincing evidence of match fixing or an intentional effort to affect the results of the Gold Cup 2015 matches," the organization said in a statement. "Each of the decisions during the quarterfinals and semifinals of the Gold Cup 2015 could be attributed to simple mistakes, errors in positioning, and/or lack of concentration.

"Based on interviews and statements from referees, it is possible that a number of external circumstances, most notably recent labor disputes by the referee group and internal disputes, were an unnecessary distraction for the referees at a critical time. In interviews, the referees admitted personal errors and apologized for them."

With regard to the assessment of the state of the referee department, CONCACAF said it also paid particular attention to the referee strikes at the 2015 Gold Cup and 2015 Toronto Pan American Games, and the overall operations of the referee department.

CONCACAF said that it has determined that the referee and match official appointment process requires reform. The confederation's current procedure differs from the guidelines provided by FIFA, and in the words of CONCACAF "has led to mistakes, valid criticism from many stakeholders, and information leaks."

CONCACAF also identified areas for administrative improvement in the planning and structure of the referee department. These improvements will address referee payment and reimbursement issues, as well as various other procedural and management functions within the referee group.

CONCACAF said it had not increased compensation for referees in recent years with the exception of Gold Cup 2013, which was done across the board for all match officials and referees, but only for that tournament. CONCACAF has reviewed the current compensation policy and is in the process of implementing new financial terms for referees and other match officials.

A CONCACAF spokesperson confirmed it has parted ways with Sonia Denoncourt, a referee from Canada who was heading up the referee department, and that a search for her replacement was underway.

CONCACAF said it will improve the match official appointment process and adopt best practices similar to those from FIFA and other world-class member associations. This new process, and enhanced procedures, are expected to serve as the foundation for a strong and effective refereeing function within the CONCACAF region.

The referee department review was conducted by Howard at the request of CONCACAF's executive committee. The review process included interviews with referees, officials, technical staff, and members of the CONCACAF referee advisory group. It also included a review of match-monitoring reports from the 2015 Gold Cup and an assessment of the referee appointment process for all CONCACAF competitions.

In addition, Howard personally monitored the process to appoint referees for the competitions that took place, or are scheduled to take place, after the conclusion of Gold Cup 2015.