Maureen Callahan's new biography revealing sordid Kennedy family secrets becomes No.1 best-seller just HOURS after release... as Megyn Kelly gives her rave verdict

Author and DailyMail.com columnist Maureen Callahan's bombshell new biography of the Kennedy family has raced to the top of best-seller lists within hours of being released.

'Ask Not: The Kennedys and the Women They Destroyed' hit shelves on Tuesday, July 2, and immediately took the No.1 spot on several of Amazon's sales charts. 

As well as claiming the top spot on the site's 'Women in History' section, it also came first in the 'Women's biographies' ranking (while the audiobook and e-book editions came in third and fourth place).

The book — which was serialized by the Mail last month — ranked in the top 10 in a host of other charts, including coming third in the prestigious 'History' category.

Most remarkable, days before it was even published and due to a large number of pre-sale orders, 'Ask Not' became Amazon's 5th best-selling new release last week.

Callahan has already received a flurry of rave reviews, including from podcaster Megyn Kelly, who described the book as 'the must-read book of the summer.'

'There's so many interesting new nuggets on this bizarre family. Trust me, you're going to want to read it and buy it for everyone you know,' Kelly said.

A similarly glowing review in The Guardian praised the book as an 'eye-opening exposé', while Town & Country magazine described it as 'a searing, no holds barred account of scandal'.

Last month, the Mail published four exclusive extracts of the book.

These included shocking new revelations such as: untold details of JFK's 1963 assassination; his wife Jackie's second marriage to Aristotle Onassis and the 170-clause prenup they negotiated; unearthed claims that could implicate 'lady-killer' Kennedys in the death of Marilyn Monroe; and a stunning new theory about the 1999 plane crash that killed JFK Jr. and Carolyn Bessette.