Essendon calls in Ziggy Switkowski to lead review ESSENDON yesterday admitted the discovery of irregular practices within its football department was the catalyst for the announcement of an external and independent review of governance and club processes. Club chairman David Evans questioned the level of supervision and procedures within its sports science area. In the wake of an Australian Sports Anti-Doping Authority's ongoing investigation into potential use of performance-enhancing drugs by players pertaining to the 2012 season, the review was approved by the Essendon board. The review will be conducted by former Telstra chief executive and Essendon supporter Ziggy Switkowski, who chairs the Australian Nuclear Science and Technology Organisation. Assisting Switkowski will be Andrew Garnham, specialist sports and exercise physician and lecturer at Deakin University. "The board and I are now aware of irregular practices by the club that are being investigated by ASADA and the AFL, and that is why we have decided to call an independent and external review into the governance and processes that have led to us being in the position we are today," Evans said. As chairman of the club I'm vary aware of my responsibilities to fix any problems the report finds. Evans said he could not elaborate on what "irregular practices" the club had uncovered because he did not want to compromise the integrity of the review or the ASADA probe. "So that's something that I prefer not to talk about at the moment, but let's say I am aware of irregular practices that did occur," he said. Evans said he was armed with more knowledge than he was three weeks ago when the club approached the league about its concerns two days before the release of the Australian Crime Commission's report on organised crime and drugs in sport. "We just want to get to the heart of what happened," he said. It'll tighten up our procedures, policies and level of supervision. Evans said ASADA welcomed the external review and that Switkowski would be given all the resources he required. While no time frame was put on the independent review, the Bombers expect it to be completed before the ASADA probe is completed. Essendon expects that recommendations will be made public. "In announcing this review, I want to make sure we are able to give answers to our members about what happened and why, and to put in place any changes needed to ensure that this doesn't happen again," Evans said. The players have been wonderful. We are staying very close to our players and I'm incredibly proud of the way they have conducted themselves. The only casualty at Windy Hill since the ASADA investigation has been high-performance manager Dean Robinson, who was stood down pending the outcome of the probe.