Marilyn Monroe had cosmetic surgery, her medical notes revealed.

A series of documents penned by Hollywood plastic surgeon Michael Gurdin and a number of x-rays belonging to the late actress will be auctioned next month, and the file - a partial medical history dating between 1950 to 1962 - appear to confirm that the blonde beauty had her jaw transformed.

Gurdin's notes make reference to a cartilage implant in Marilyn's chin, which was inserted in 1950 and later slowly begun to dissolve.

Martin Nolan, executive director of Julien's Auctions, who are administering the sale in Beverly Hills, California on November 9 and 10, said: ''Nobody really thought about Marilyn Monroe having plastic surgery. It was always speculation - did she or didn't she?

''They thought she was such a natural beauty, they didn't want to believe.

''Also at that time, going back to the 1950s, people didn't go for plastic surgery procedures. This is very, very new.''

The X-rays are dated June 7, 1962, after Marilyn saw Gurdin following a late night fall and include images of the 'Some Like It Hot' star's frontal facial bones, a composite right and left X-ray of the sides of her nasal bones and dental X-rays of the roof of her mouth.

The documents - which were given to the unnamed seller as a gift from the surgeon - are expected to fetch between $15,000 and $30,000 at auction.

Two months after the X-rays were taken, the 'Gentlemen Prefer Blondes' star died aged 36 from an overdose of barbiturates. The death was ruled a probable suicide.