Between 1956 and 1961, Marilyn Monroe was married to one of the greatest American playwrights of all time, Arthur Miller. It was her third and last marriage, a controversial relationship that was constantly scrutinized and ended unhappily.

Now, never before seen photographs of Norma Jeane Mortenson have been uncovered, and they might reveal previously unknown pregnancy. These extraordinary shots of the 1950s sex symbol were sold at an auction in Los Angeles, California in November 2016.

One of the six photos dubbed the ‘Pregnant Slides’

The price paid for the six color shots last year was $2,240. Judging by the high publicity they have garnered, it has become clear that the amount can be considered dirt-cheap. It is speculated that the seller was not aware of the cultural significance the pictures might possess.

The shots were taken on July the 8th, 1960 outside the Fox Studios in New York City

The images used to belong to one of Monroe’s closest friends, Frieda Hull. They show a prominent belly, which many believe is the sign of early pregnancy.

This has given further fuel to the rumors about a child fathered by Monroe’s lover at the time, iconic Italian-French actor Yves Montand. They met on the set of the 1960 musical comedy Let’s Make Love and started a well-publicized affair. The pregnancy was kept secret and ended with a miscarriage.

The legendary pop icon was 34 at the time the pictures were taken

Frieda Elizabeth Hull, Marilyn Monroe’s friend who passed away in 2014

Frieda Hull’s and her next door neighbor Tony Michaels, 56, were close friends in the latter part of her life. She shared numerous stories about Monroe with him, and had confirmed the pregnancy before she passed away.

“Frieda was very proud of those slides and she was very proud to keep them a secret until the day she died. But she told me the story behind them, that Marilyn got pregnant by Yves Montand. It wasn’t a guess or a presumption, it was something she knew for sure, she was very close to Marilyn. As far as she was concerned Marilyn was pregnant in the summer of 1960 and the slides prove it”, Michaels revealed.

Monroe suffered three miscarriages before this pregnancy and suffered from a condition called endometriosis which causes severe menstrual pain. Despite desperately wanting a child, she never gave birth.

Monroe was born Norma Jeane Mortenson in Los Angeles in 1926, where she also passed away in 1962 aged 36

The star’s marriage to Arthur Miller was notoriously unhappy and Tony Michaels revealed how the affair with Montand happened during the filming of Let’s Make Love.

“She always called them that, she told me the father of the unborn child was Yves Montand, she told me the story of how Arthur got called away and Yves Montand’s wife got called away and they stayed together in a Beverly Hills Hotel bungalow and they had an affair”.

In May 1960, Miller found out about the affair and their marriage was soon crumbling. By August the same year they were not on speaking terms anymore and soon Monroe moved out of their shared apartment.

She passed away two years later, on August the 5th, 1962 of acute barbiturate poisoning.