Washington (CNN) Former FBI Deputy Director Andrew McCabe says that his book's release date has been delayed from December to February because the bureau has not yet completed its required pre-publication review of the manuscript.

In a statement to CNN issued through his spokesperson, McCabe suggested that politics could be at play.

President Donald Trump frequently attacked McCabe during the former FBI deputy director's tenure, with the president tying McCabe to his 2016 presidential opponent Hillary Clinton.

"I am disappointed that we have had to substantially delay the publication date for my book because the FBI's review has taken far longer than they led me to believe it would," McCabe said in the statement Thursday. "Having been singled out for irregular unfair treatment over the past year, I am concerned it could be happening again."

"I am looking forward to sharing my story with the public, and now look forward to doing so in February," McCabe added.

Read More