The release of critical documents related to “Crossfire Hurricane,” the FBI’s investigation of former President Donald Trump’s 2016 campaign, was slow-walked and, in some cases, blocked by CIA Director Gina Haspel, former Deputy National Security Adviser Kash Patel said in an interview Sunday. Trump, on his last night in office, ordered the declassification of previously confidential documents related to the flawed counterintelligence investigation launched by the FBI in July 2016 to investigate allegations of Russian interference in the 2016 U.S. presidential election. Patel, who assisted the House Intelligence Committee in uncovering wrongdoing within U.S. intelligence in the probe, said Haspel worked to prevent key documents from being declassified. Haspel resigned from the agency on Jan. 19 without explanation. “The institutional heads of places like the CIA and the FBI were always fighting the release of any documents, and they would claim national security issues—you’re going to harm a source or you’re going …