A set of six photographs taken by a friend of Marilyn Monroe have sparked a debate over whether the screen icon may have been secretly pregnant.

The images, which were taken at Fox Studios in July of 1960, show Monroe arriving at a test shoot for The Misfits with a more rounded tummy than usual, leading many to speculate that she was pregnant at the time. She would have been 34 when the image was taken, two years before her death. The photos, dubbed 'the pregnant slides' were taken by the photographer Frieda Hull, one of the Sixers, a group of Marilyn Monroe fans who would wait for the star outside her hotel. Hull eventually became a friend of the Some Like It Hot star, real name Norma Jean Baker, and her candid snapshots and various other items were auctioned by Hollywood memorabilia experts Julien’s of Los Angeles last year. While Monroe's struggle to conceive a child are well documented (she suffered numerous miscarriages as well as an ectopic pregnancy), it is not known if there is proof she was pregnant at this stage of her life. The pregnancy rumour was compounded by the man who bought the photos; Las Vegas croupier Tony Michaels, a friend and next-door neighbour of Hull's, who claims Marilyn was pregnant by the Italian-French actor Yves Montand, her co-star in Let’s Make Love. Both were married to other people at the time; Monroe to Arthur Miller and Montand to the French film star Simone Signoret. Referring to the affair, Signoret famously said : 'If Marilyn is in love with my husband it proves she has good taste, for I am in love with him too.' Michaels says Hull confided in him that Monroe later lost the baby. Speaking to the Daily Mail, he said: 'Frieda believed that it wasn't exhaustion that landed her in hospital, she said it was a nervous breakdown and she lost her baby. 'And all she told me was that Marilyn has lost the baby, it was never made clear whether that was by way of a miscarriage or even an abortion, and I never thought to press her on it.' Hull passed away in 2014, and with Monroe and Montand long dead, it looks as if we'll never know the truth. Pictures: Tony Michaels/Mega/ DM