Hot on the heels of the busty photographs of the late starlet playfully posing for her make-up artist, come more shots taken by Allan 'Whitey' Snyder.
Monroe asked her trusted friend to help her relax before filming and the natural joy she exuded in those moments can be seen again in these new snaps.
They show the dreamy star laughing unrestrainedly and larking around on set before the cameras roll on the set of The River Of No Return in 1954.
Marilyn Monroe on the set of River of No Return in 1954, taken by Snyder
Snyder died in 1994 and the pictures were released after his archive of photos emerged for sale at auction in Beverly Hills this weekend.
There are dozens of pictures from the sets of other films including Gentlemen Prefer Blondes, The Prince and the Showgirl, Niagara and Something's Got to Give.
The archive will be sold in Beverley Hills, California, during a two-day sale starting on March 31.
This shot by Romanian-born photographer Andre de Dienes was taken in 1955 by which time Marilyn was about to become a global star
The archive includes letters and other ephemera and is expected to fetch thousands of pounds when it all goes under the hammer at auction.
Darren Julien, of Julien's auctioneers, said: ‘Whitey Snyder died in the 1990s and these items have come from his estate, so they have never been seen before.
‘Whitey was Marilyn's make-up artist for 16 years and had unlimited access to her.
‘They met when Monroe had her first screen test at 20th Century Fox in 1946.
Monroe, by now a superstar, pictured relaxing at home in a shot from 1962 taken by photographer George Barris
‘Sometimes, especially in the early days of her movie career, she would get nervous on set and Whitey would photograph her and she would come to life.
‘It would take her mind off all her problems and this would happen during down time on film sets.
‘Some of them even show her in costume and they were never intended to be released to the public.
‘There are many other items in the archive as well as photographs and collectors and institutions will be keen to own them.’
The sale also includes a rare calendar with a picture of a naked Monroe on it.
