As fans worldwide mark 50 years since her untimely death, a collection of rare Marilyn Monroe photographs immortalising the American blonde bombshell went on display in Warsaw Monday. Poland's State Treasury obtained the candid shots of Monroe by a friend. Milton Green, in a collection of nearly 4,000 photographs it received as part of a 1995 foreign debt settlement. The collection also contains images of Frank Sinatra, Liza Minnelli, Marlon Brando, Judy Garland and Marlene Dietrich and is to be auctioned off later this year. Monroe is snapped dressed in jeans fixing her lipstick and hair, eating a meal and coyly chatting on the phone in several photos, which will be on display until September 6 at the Association of Polish Artistic Photographers on Warsaw's Royal Castle square. According to the association, some of the images of Monroe have not been seen before. No date has yet been fixed for the auction, but Poland's treasury expects it to go ahead before the end of the year and fetch upwards of $680,000 (560,000 euros). Some 300 Monroe fans gathered Sunday at the Los Angeles cemetery where she is buried, commemorating the iconic sex symbol on the 50th anniversary of her death. The actress died on August 5, 1962 from a barbiturate overdose at her home in the upscale Brentwood neighbourhood.