The Department of Justice has opened a criminal investigation into whether former national security adviser to US President Donald Trump John Bolton mishandled classified information in his book The Room Where it Happened, according to The New York Times.A grand jury, convened by the Department of Justice, has issued subpoenas for the Javeline Agency that represents Bolton and the records of communications from the book’s publisher Simon & Schuster. “Ambassador Bolton emphatically rejects any claim that he acted improperly, let alone criminally, in connection with the publication of his book,” Bolton’s lawyer Charles J. Cooper said. Bolton submitted a copy of his book for review in December to the National Security Council and was told he had completed the necessary edits for the manuscript, but did not receive a letter saying that the review was complete. After he received no clear answer about confirmation, Bolton went ahead with publishing the book based on the NSC statement that the review was over, according to the NYT.A few weeks before the book was to be released in June, the council attempted to prevent its release, saying that it still contained classified information. Cooper accused the Trump administration of slowing down the review process to keep Bolton from embarrassing the administration.The book was released after a federal judge determined that it was too late to rule in favor of the Trump Administration that had sued Bolton to prevent the book’s release, because the book had already been shipped to distributors and news agencies, according to the Washington Times. Bolton also faces civil litigation that could mean he would be forced to forfeit all proceeds from the sale of the book, the NYT reported.