Washington ( CNN ) -- He 's the leader of the Department of Veterans Affairs , which runs the VA hospitals where dozens of U.S. veterans died waiting for simple medical screenings . Yet in the six months that CNN has been reporting on these delays , Eric Shinseki has been silent . And he has n't spoken out on the matter to any other news organization , either . Early Friday evening -- after this story appeared on CNN.com -- the VA gave a response , via spokesman Drew Brookie . He explained that the VA 's inspector general 's office ( referred to as OIG ) , which is probing the matter , `` advised VA against providing information that could potentially compromise their ongoing investigation at the Phoenix VA Health Care system . '' `` Accordingly , VA may not be able to respond with respect to specific inquiries that may fall within the bounds of the OIG investigation on this subject , '' Brookie said . `` VA will work with OIG to ensure that any information provided balances our need to keep the public informed with the obligation to preserve the integrity of the OIG 's investigation . '' We first began examining the delays in appointments and care for veterans last fall , and immediately reached out for an interview with Secretary Shinseki on November 12 . Our initial report on delays in care at VA hospitals in Georgia and South Carolina published a week later . Since then , we 've submitted numerous written requests and last month we verbally requested an interview with Shinseki at an April 9 House hearing on the delays prompted in part by CNN 's reporting . Most recently , we started looking into the Phoenix VA , where sources told us that the hospital concocted an elaborate scheme to cover up long wait times there . The sources said more than 1,400 vets were placed on the purported secret list and that documents were shredded to hide the evidence . According to sources , at least 40 U.S veterans died waiting for care at the facility , many of whom were on the list . According to CNN 's sources and documents , more than 120 veterans -- including the 40 in Phoenix -- have died , are dying or have suffered serious injuries waiting for care at VA facilities . The VA has acknowledged that 23 veterans have died as a result of delayed care in recent years . Our requests for interviews with Arizona officials were repeatedly denied , until finally the local top VA officials in Phoenix agreed to an interview on Tuesday -- nearly a week after our initial story aired on CNN 's AC360 and CNN.com . The Arizona officials told CNN Tuesday they had never instructed their staff to create a secret list , or to maintain a secret list , or to shred any evidence , and they said they never issued any instructions about it to their staffs . They acknowledged an electronic waiting list for veterans but said there may have been confusion among their staff about how it worked . They admitted some patients on the waiting list have died , but that they said they do not know if those deaths were tied to delays . CNN 's exclusive investigation quickly drew attention in Washington : on Monday -- a day before the Phoenix VA officials agreed to speak to us -- President Barack Obama announced he has called for an investigation into what has happened in Phoenix . Shinseki issued a written statement Thursday , announcing that the director of the Phoenix Veterans Affairs Health Care system and two others have been placed on administrative leave amid claims of a secret waiting list and claims that 40-plus veterans died waiting for care . `` We believe it is important to allow an independent , objective review to proceed , '' Shinseki wrote . `` ... These allegations , if true , are absolutely unacceptable and if the Inspector General 's investigation substantiates these claims , swift and appropriate action will be taken . '' Still , Shinseki has refused all CNN requests for an interview . Shinseki has served as VA secretary since 2009 , appointed by President Obama who hailed him as someone who `` always stood on principle . '' The former Army Chief of Staff under the Bush administration earned high praise among Iraq war critics for his testimony before the Senate Armed Services committee one month before the U.S. invasion into Iraqi , saying he believed `` several hundred thousand troops '' would be needed to keep order in a post-invasion Iraq . That was more than double the number of forces the Pentagon had estimated . `` No one will ever doubt that this former Army chief of staff has the courage to stand up for our troops and our veterans , '' Obama said when he nominated Shinseki to the post . January : Veterans dying because of health care delays . January : Congress demands answers . November : Georgia VA hospital apologizes . November : A dire situation in South Carolina . Watch Anderson Cooper . 360° weeknights 8pm ET . For the latest from AC360° click here .
NEW : VA : Want to balance keeping public informed , monitor investigation 's progress . CNN has reported dozens of veterans have died waiting for care at VA hospitals . This year , sources told CNN the Arizona VA has a scheme to cover up the delays . Arizona VA officials have denied that .