Comey book: Most embarrassing revelations about Donald Trump made by the fired FBI director

A new book from the FBI director fired by Donald Trump is revealing some of the most embarrassing parts of Donald Trump's life.

James Comey's new book – an autobiography that focuses on his life, but the reception to which has focused on the parts that overlap with the president – shows some of the thinking behind Mr Trump's strangest decisions and behaviour. He also attacks the president's character, calling him unethical and "untethered to truth".

It is the second book in recent months to cause great embarrassment to Donald Trump, revealing his secrets and new parts of his character. But Comey's book could be even more decisive than Michael Wolff's Fire and Fury – it is written from within the ongoing investigations into the president's connections with Russia, and is likely to serve as a key part of the evidence in those proceedings.

Here are some of the most remarkable observations and stories to come out of the book, ahead of its release next week.

Physical stature (or lack thereof)

The 6-foot-8 Comey describes Mr Trump as shorter than he expected with a "too long" tie and "bright white half-moons" under his eyes that he suggests came from tanning goggles.

Mr Comey also writes that he checked the size of the president's hands. They were "smaller than mine but did not seem unusually so", he writes.

Spy dossier

Perhaps the most unusual part of the revelations so far is Mr Comey's suggestion that Donald Trump was obsessed with the allegation, contained in an ex-spy's dossier, that he had engaged in lewd behaviour with sex workers while in Russia. The president kept asking the FBI boss about it, he says, suggesting that the organisation could prove the allegations false – apparently in an effort to keep Melania from being upset about them.

He writes that he told Trump about the dossier because it was the FBI's responsibility to protect the presidency from coercion related to harmful allegations, whether supported or not. Comey said he left out one detail involving an allegation that the prostitutes had urinated on a bed once used by the Obamas.

Trump raised the subject again a week later, after the dossier had been made public. He then told Comey, the director writes, that he had not stayed in the hotel and that the most salacious charge could not have been true because, Trump said, "I'm a germaphobe. There's no way I would let people pee on each other around me. No way."

Mr Comey writes that Trump raised the issue again, unprompted, during their one-on-one dinner at the White House and it bothered the president that there might be even "a one percent chance" his wife might think it was true.

Mr Comey then registers surprise, writing that he thought to himself "why his wife would think there was any chance, even a small one, that he had been with prostitutes urinating on each other in a Moscow hotel room."

Trump is a 'mafia don'

Mr Comey compares Trump to a mafia don and calls his leadership of the country "ego driven and about personal loyalty."

He says he had flashbacks to his time investigating the Italian Mafia as a federal prosecutor in Manhattan, thinking that Trump "was trying to make us all part of the same family."

Additional reporting by agencies