Washington - Officials at the philanthropy founded by Bill and Hillary Clinton admitted on Sunday that the organisation has made financial disclosure "mistakes" and vowed to quickly correct the errors.The acknowledgement of the problems with the Clinton Foundation's financial statements, which acting CEO Maura Pally said were unintentional, were made in a lengthy statement posted on the clintonfoundation.org website.Pally, who said a voluntary external review is under way, wrote that "our error was that government grants were mistakenly combined with other donations".She insisted those grants have been properly listed and can be viewed on the website in the foundation's audited financial statements."So, yes, we made mistakes, as many organisations of our size do," Pally said."But we are acting quickly to remedy them and have taken steps to ensure they don't happen in the future."Allegations surrounding the Clinton family's charitable organisation has mired the early days of Hillary Clinton's presidential campaign in controversy.The former first lady ended her involvement with the foundation earlier this month, shortly after announcing her 2016 White House bid. The sole announced US Democrat presidential contender, Clinton has faced unsettling new accusations of financial conflicts of interest because of her ties to the foundation, some of which appear in a new book, Clinton Cash, to be published May 5.In the book, author Peter Schweizer makes incriminating accusations about foreign contributions to the group, which was founded by former president Bill Clinton in 2001.Several donations from foreign governments are put under the microscope in the book, in which Schweizer suggests - without direct evidence - that Clinton traded favours for donations while she was secretary of state from 2009 to 2013.Speaking early on Sunday on ABC television's This Week programme, Schweizer called for a criminal investigation into the Clinton Foundation's funding."This is part of the broader pattern. You either have to come to the conclusion that these are all coincidences or something else is afoot," he said.Democratic groups have labelled Schweizer - a former speech-writing consultant to former president George W Bush and advisor to 2008 vice presidential candidate Sarah Palin - as a partisan activist, and call the book a conservative hit job on Clinton.