A DNA investigation is currently being carried out by the Clan Munro USA, who found that the American sex bomb has roots in Ross-shire.
They discovered that Monroe, who would have turned 90 this week, descended from a Scots soldier exiled to America after the English Civil War.
And now the search is on for her relatives - with free DNA tests being offered to Munros with Ross-shire and Highland origins.
The American icon was born as Norma Jeane Mortenson but took her screen name from her mother, Gladys Pearl Monroe.
The research made use of DNA provided by a male-line relative Marilyn Monroe’s grandfather, Otis Elmer Monroe.
It suggested a link to a John Munro from the Tain area who traveled to America in the mid-17th century.
Many Scots fought as mercenaries in the English Civil War, most of them on the Parliament side. Munro may have fought with the Royalist troops of King Charles I.
It is likely he was sent to Boston to be sold into forced servitude after being captured following Charles’s defeat by Cromwell at the battle of Worcester in 1651.
It is believed that John, who eventually settled in Bristol, Rhode Island, was the son of a Robert Munro from Aldie, near Tain.
Mark Monroe of Austin, Texas said: “Like all clans, Munro men, however they spell the name, have a mix of male genetic lines. Last year we found that many Scots Munros are related to US President James Monroe.
“Descendants of John of Rhode Island also form a large genetic group in present-day America and it would be good to find their relatives among present-day Scots men.”
The project also has the backing of Colin Munro, who belongs to the Foulis male line based in Ross-shire.
He said: “In addition to trying to prove a Ross-shire origin for Marilyn’s ancestor, it would be good to establish the main male ancestral DNA types in the Munro home territory.”
“The expatriate Monroes and so on of whatever DNA pattern, who form the majority of those tested, are very keen to prove their Scots ancestry.”
DNA testing for the Munro DNA Project is carried out by Family Tree DNA, Inc. of Houston, Texas. Project administrators are volunteers on behalf of Clan Munro USA and state that they have no commercial interest in the project.
All testing was paid for by participants themselves, or by members of Clan Munro USA.
Margaret Bardin, volunteer administrator of the Munro DNA project at Family Tree DNA, added: “We have a limited number of free tests and it’ll be first-come first-served!”