Former Federal Bureau of Investigation (FBI) Director James Comey
Former Federal Bureau of Investigation (FBI) Director James Comey. Reuters

James Comey's upcoming book has offered a remarkable look into the former FBI director's relationship with President Donald Trump, the media reported.

Comey's recollections take aim at the President's disposition, which he says created "the forest fire that is the Trump presidency", CNN reported on Thursday.

"This President is unethical, and untethered to truth and institutional values," Comey wrote.

"His leadership is transactional, ego driven and about personal loyalty."

After Trump fired Comey as FBI director last May, news emerged that Comey kept contemporaneous memos on his conversations with Trump, claiming Trump had asked him to end the investigation into former National Security Adviser Michael Flynn.

Following reports of the memos, Deputy Attorney General Rod Rosenstein appointed former FBI Director Robert Mueller to lead a special counsel probe into alleged Russian interference in the 2016 election and potential coordination between Trump's associates and Russia.

Comey went on to deliver his testimony before the Senate Intelligence Committee, where he accused the President of lying about their interactions.

In his book, Comey wrote about Trump's concern over allegations about blackmail and prostitution contained in an opposition research dossier on Trump written by former British intelligence office Christopher Steele, which Comey said the President referred to as "the golden showers thing", reports CNN.

Comey portrays the President as a bully and a liar who sought to muscle federal investigators like himself.