Had she lived, Monroe would have been 80 in June, but her early death at 36, preserving her beauty forever on celluloid, has helped make her's the world's most valuable posthumous celebrity image - worth at least $8m a year. This pot of gold has now provoked a clash between the descendants of four photographers who took her picture, and the ultimate inheritor of Monroe's estate, Anna Strasberg, widow of the star's acting coach and friend, Lee Strasberg.
And, this being a Monroe affair, the image dispute is but part of the constant circus of exploitation that has followed this most vulnerable of screen stars far beyond her Los Angeles grave. Another lawsuit is now under way, launched by those associated with a film about her first husband, Jim Dougherty; the authenticity of many of the 800 items in a Marilyn Monroe exhibition is being contested; newly opened FBI files are stoking the never-resolved rumours of the Kennedys' involvement in her death; and the woman who has already inspired more than 300 books will soon become the subject of a contentious new biopic by Tom Hanks.
But the image rights lawsuits - which centre on publicity rights for the pictures, as well as alleged restraint of trade over their reproduction - are the most valuable of these Monroe properties.
Among the photographs are Sam Shaw's picture of Ms Monroe's skirt billowing over a grate, and Tom Kelley's famous "red velvet" shoot, later to become Playboy's first ever centrefold. The pictures' copyright has always remained with the photographers and then with their offspring, but commercial use of Monroe's image was bequeathed to Strasberg. His third wife, Anna, 36 years his junior, whom he married at 67, six years after the actress's death, inherited them upon Strasberg's death in 1982. She employs US-based image specialists CMG Worldwide to manage the pictures' publicity rights.
It was all so much simpler on the day the legendary Kelley image was originally captured, at the photographer's Los Angeles studio - 27 May 1949. The unknown Monroe was paid only $50 for the shoot, telling the photographer and his wife that she needed the money to pay for the recovery of her car from a nearby pound.
After the shoot, the three went together for a bowl of chilli at a restaurant, while Kelley's brother Bill went to the local Kodak shop, complete with a bottle of Scotch as a bribe to make sure that the risqué portraits were developed. Now this classic picture is one of those at the heart of the legal tug of war taking place in three separate states. It is a struggle that Kelley's son, also called Tom, remains confident of winning.
A photographer himself, Mr Kelley Jnr said he and the other descendants had finally lost their patience with the "bullying" and "greed" of CMG, which had been demanding up to 90 per cent of profits from sales of the images. "I said, you want a showdown? OK, we're going to have it here and now," said Mr Kelley. "We have tried to work with them, but now it's up to the courts to decide. What they stand to lose is all the rights, all the publicity for Marilyn, which is huge. We're talking about tens of millions of dollars here."
His sentiments are echoed by Sam Shaw's daughter, Edie, who was herself very close to Monroe. "Protecting Marilyn and protecting my father's name is always on my mind," she said. "There were only a handful of photographers Marilyn ever worked with and she got very attached to them. She would think it terrible that they're being told they can't use their pictures of her."
The case centres on whether Ms Monroe should be considered a resident of New York or California at the time of her death. If she is judged to have been a New Yorker, any publicity rights died with her on that fateful evening in 1962. If she was a Californian - where she was born and ultimately died - they will remain under the control of her estate for 70 years.
The lawyer representing the Kelleys and the family of one of the other photographers, Milton Greene, is sure the courts will rule Ms Monroe is a New Yorker - potentially demolishing the Marilyn interests of both CMG and Ms Strasberg.
"The factual nub we're going to dance around is Marilyn's domicile at the time of her death," said Surj Soni, speaking from his office in California.
"She died in Los Angeles, but at the time of her death, she lived in New York, she owned an apartment in New York and she was a registered voter in New York.
"After her death, the estate of Marilyn Monroe filed probate and declared she was a domicile of New York City."
But the owner of CMG, Mark Roesler, accused the photographers' families of "trying to hide under a technicality". He said: "The big picture is that Marilyn Monroe left a body of intellectual property rights after she died. My client has the only trademarked rights to the name of Marilyn Monroe."
He added: "Marilyn Monroe knew better than anyone how valuable and marketable her image was. She'd be very supportive of her agents, and appalled that different photographers were trying to rip her off."
The other descendants of the four photographers see things differently. Mr Greene's son Joshua - whose father was perhaps the closest of them all to Monroe, having invited her to live with his family for two years - was particularly outspoken when contacted by the IoS.
"The fact of the matter is that they [CMG] are being greedy and unreasonable. They are like a schoolyard bully, beating his chest," he said.
"We've taken enough crap from these people. It's a game of intimidation and there are laws that protect us against restraint of trade. The fact is that Marilyn hated people like this - it's so ironic.
"Marilyn would take sides with us," continued Mr Greene. "But she would never have let things get to this point in the first place. Obviously it is in everybody's interests to keep her likeness seen.
"We're just trying to turn this curse around."Reuse content